Allen-Bradley 3500-TBX Interface Board Version 3 Firmware

Purpose of Manual:
This Manual is intended for use by personnel familiar with the functions of solid-state Drive equipment. Included in this manual are reference materials, which will allow the reader to operate, maintain, troubleshoot and perform basic adjustments to the 3500-TBX Interface Board. This manual applies to Version 3 of the firmware.

General Description:
The Bulletin 3500-TBX Interface Board is a direct replacement for the 189-TSI, Tach Serial Interface Board for Bulletin 3500 AC Drives. When combined with the 3400-TBD, 3500-TBX becomes an option for Bulletin 3400 DC Drives. It can also replace the 3500-NA2 PLC Interface Module in Bulletin 1352C Scalar and Vector Drive applications. The 3500-TBX Board includes a Host/Plug Interface, which can be used in place of the Drive
Protocol Channel 2-20 mA Current Loop Interface to connect to Allen-Bradley Data Highway Plus and/or Remote 1/O communication networks. The microprocessor on the board maintains a complete Drive Parameter Table Image with special services to communicate parameter information to the Network Drive Maintenance System Software.

The microprocessor controls the following interfaces:

• 1 Allen-Bradley Remote I/O (RIO) channel
• 1 Allen-Bradley Data Highway Plus (DH+) channel
• 4 digital inputs
• 4 digital outputs
• 2 Drive protocol channels

The following interfaces are not under microprocessor control:

• 1 Remote Control Panel (CP2) Interface
• 1 Digital Reference Controller (DRC) Interface
• 1 Pulse Tachometer Interface ("drive speed feedback" tachometer)

For coordinated sectional Drive systems, a PLC communicates with the Drive on Channel 1, with the TBX Interface converting the remote 1/O signals to the optical signal required by the Drive. A Block diagram of the 3500-TBX is shown in Figure 1.

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Specifications:
Environment

Electrical Specifications:
Power Supply
The 3500-TBX Interface Board requires a single power source of 18V DC to 32V DC at less than 2.5A. The same input that powers the 189-TSI or the 188-IOC is sufficient to power the 3500-TBX via connector X8. The 3500-TBX can provide 12V DC at 160 mA or 24V DC at 200 mA to a pulse tachometer. Data Highway Plus Link Channel A on the Bulletin 6690-DP2 Data Highway Plus/Remote I/O Adapter (herein after referred to as Adapter Plug) connects to the 1771 Data Highway Plus network using standard twin axial cable (1770-CD or Belden 9463) and a standard 3-pin connector. A Din connector on the Adapter Plug can be used to connect a personal computer to the Data Highway Plus with cable 1784-CP6 and a 1771-KT Card. The Adapter Plug supports 57.6 k, 115.2 k and 230.4 k baud network speeds.

Remote I/O Link
Channel B of the Adapter Plug connects to the 1771 Remote 1/O Link using standard twin axial cable (1770-CD or Belden 9463) and a standard 3-pin connector. The Adapter Plug supports 57.6 k, 115.2 k and 230.4 k baud link speeds.

DRC Communication Link
The receive and transmit 20 mA current loop signals are converted to optical signals for the Drive at the baud rate set in the DRC. The 3500-TBX connector X2 pinout matches the 189-TSI X2 pinout for this connector. The connector can be wired to provide a source for the current loops.

Control Panel (CP5)/DMS Communication Link
The receive and transmit 20 mA current loop signals are converted to optical signals for the Drive at the baud rate connected. Receiving and transmitting is via Drive Channel 1 with arbitration of transmission taking place on a first served basis between the control panel and the other selected Channel 1 transmitter. X6 also supplies power to the control panel. The 3500-TBX Connector X6 pinout matches the 189-TSI X6 pinout for this connector.

Tachometer Connection
This converts 2 channels of digital pulse encoder to optical signals required for Drive operation. It also supplies 13/24V DC to the Tach and provides a coast stop function when used in place of 189-TSI or 188-IOC. The 3500-TBX connector X3 pinout matches the 189-TSI X3 pinout for this connector.

Optical Communication Link
V l and V2 transmit 2 channels of tach pulses to the Drive. V3, V4, V5 and V6 transmit and receive 2 channels of Drive communication protocol. The channel 2 baud rate can be 4800 baud or 9600 baud. The Channel 1 baud rate can be 4800 baud or 9600 baud if the 3500-TBX is selected to use Channel 1 for Remote 1/O. The optical links use Hewlett Packard optical receivers and transmitters.

TTL Communication Link
TTL signals for both communication channels are provided at connector J2 for conversion to full duplex 20 mA current loop by the 3400-TBD board.

DDC Link
The 3400-TBD board converts the TTL signals that connect to the optical receivers and transmitters on the TBX Board to a full duplex 20mA current loop for use with the Bulletin 3400 Digital Drive Controller (DDC). Connector X12 is used for TBX Channel 1 and X13 is used for TBX Channel 2. The pinouts for this connector match the X2 connector on the TBX or the 189--TSI.

Digital Inputs
Four digital inputs are available at connector X10. They are rated for 120V AC and will sink up to 5 mA. The digital inputs can be monitored by Remote I/O, Data Highway Plus and the drive.

Digital Outputs
Four digital outputs are available at connector X11. The contacts are rated for 120V AC at 1A continuous and 3A inrush. The digital outputs can be controlled by Remote I/O, Data Highway Plus or the drive.

Connection and Indications Setup
Switch Selections
The 3500-TBX Interface Board provides DIP switch and jumper settings (Figure 2) for various configurations. Switch 1 selects the baud rate and local node address for the Data Highway Plus. (See Figure 4 for settings.)

Switch 2 selects whether the master for Channel 1 is connected to the 20 mA current loop or to the Remote I/O link (Figure 4).

Jumper J3 selects write protect/enable for the EEprom on the 3500-TBX cards (Figure 4).

IMPORTANT: Remote I/O configuration is provided through software parameters.

3500 AC Drive Connections for startup
Before any AC drive control card can be powered up, the power connection to the 3500-TBX Board connector X8 and the proper connection to coast stop relay connections at connector X3 must be established. Vector drives require that the tach be connected to connector X3 and the appropriate fiber optic cables connected between 3500-TBX and the drive. Drive Channel 1 and/or Channel 2 fiber optic cables must be connected for proper communication and operation of the 3500-TBX. 3500-TBX Channel 1 will connect to drive Channel 2 when replacing NA2 with 3500-TBX.

IMPORTANT: Longer cables are necessary than those used with the 3500-TSI or the 3500-IOC Card. These cables may also require a different type of connector on the drive end if an earlier version of the Control Card is used.

Parameter Setup
Last Parameter To Initialize
To activate the "Short Initialization Mode", set parameter "HIGH _INIT" (Parameter 4194) to zero. No "stale" flags are set and the 3500-TBX is placed in the normal operating mode immediately.

To activate the "Long Initialization Mode", set parameter "HIGH INIT" to a non-zero value of the highest drive parameter the 3500-TBX should read before completing initialization.

IMPORTANT: When this parameter is non-zero, it is forced to a minimum value of 255. It must have a value less than or equal to "LAST_SAMI_ADDR" (Parameter 4157). All parameters-from 1 through "HIGH_INIT" are read from the Drive, except for those which are part of the trend buffers.

Last Used Sami Parameter
Set "LAST_SAMI_ADDR" (Parameter 4157) to a value that represents the highest number parameter in the Drive that you want the 3500-TBX Board to recognize or scan for "stale" and "update" flags. A minimum value of 255 is enforced.

RIO Setup
RIO RACK-ADDRESS (Parameter 4152) - Set this parameter from 1 to 63 to represent the adapter rack address on the Remote I/O network for this Drive. Duplicates are not allowed.

IMPORTANT: This is the decimal rack address, not the octal address.

RIO_"BAUD_RATE" (Parameter 4153) - Set this to 0 for 57.6 k baud 1 for 115.2 k baud or 2 for 230.4 k baud. The baud rate must match the baud rate of the scanner.

RIO-RACK-SIZE (Parameter 4154):

• 1/4 Rack
• 1 - 1/2 Rack
• 2 - 3/4 Rack
• 3 - Full Rack

A FULL Rack represents 8 Groups or 8-16 bit words of the input and output tables of a PLC, while a 1/4 Rack represents 2 Groups. The 3500-TBX can handle the full 8 words in and 8 words out.

RIO LAST-RACK STATUS (Parameter 4155) - If TBX is less than a full rack, 0 tells the scanner to scan further, while 1 tells the scanner that this is the last rack. If the RIO is defined as less than a full rack, this parameter defines if there are any other module groups within the current "logical" rack. For example: If this TBX is defined as "rack 3, module groups 0-3" (1/2 rack), and another TBX is defined as "rack 3, module groups 4-T' (1/2 rack), the first TBX should have Last-Rack-Status set to 0, and the second TBX should have Last-Rack-Status set to 1. If the TBX is defined as a full rack, this word will always be 0.

RIO STARTING_MODULE_GROUP (Parameter 4156):

• 0 - Group 0
• 1 - Group 2
• 2 - Group 4
• 3 - Group 6

The "Scatter" and "Gather" tables are zero justified when communicating with the SAMI Table Manager (STM). This parameter offsets the block of remote I/O parameters when less than a full rack is used.

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Adapter Plug
The Adapter Plug provides an interface for one channel of Data Highway Plus (DH+) and one channel of Remote 1/O (RIO). Standard three pin, PLC screw terminals are used to connect both channels. A third, 8-position Mini Din connector, is available to connect the DH+ (Channel A) to a personal computer. A special cable is required to complete the interconnection.

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Each DH+ channel LED indicator can be interpreted as shown in Table 1. Included in the interpretation is a description of the LED, the significance of its color indications and if any action is required due to its color display.

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The 3500-TBX board contains interfaces between the driver and various sensing points, control points, operator interface devices and communications channels. The TBX utilizes an 80C188 microprocessor with software written in the "C" programming language and assembly language. A real-time, multi-tasking operating system is used in the 3500-TBX. Hardware in the 3500-TBX is initialized and controlled by tasks which pass information to each other with messages controlled by the operating system. Interrupt handlers may also communicate with tasks via operating system messages or event flags.

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Parameter Management
Refer to Figure 1 (Hardware/Software Interface Diagram) and Figure 9 (Task Block Diagram), to better interpret the following text.

SAMI Parameter Table
The SAMI Table is central to the operation the SAMI drive controller. It contains all parameters needed for operation of the drive controller. The TBX maintains an image of the drive controller's SAMI Table. The SAMI parameters are addressed as words starting with one.

The SAMI Table image consists of the following components:

• Parameters 1 through 499: for drive control
• Parameters 500 through 1299: for trend data
• Parameters 1300 through 4095: for function block programming/future expansion

A complete definition of the parameters for these components can be found in the applicable Allen-Bradley Digital Drive Control Instruction, Maintenance and Troubleshooting Manual.

In addition to maintaining an image of the SAME Table, the TBX has an extension of that table, from parameter 4096 through 4351. This extension is used for storage of parameters, which are unique to the TBX.

In the TBX SAMI Table image, there are two flags associated with each parameter. One flag, "update drive", indicates that the corresponding parameter in the drive controller's SAME Table needs to be updated.

The second flag, "stale data", indicates that the parameter needs to be updated with the corresponding value from the drive controller's SAMI Table.

Certain parameters have an associated "update interval". The TBX updates the corresponding parameters in the drive controller's SAMI Table as required by these intervals.

There is a "transfer function" which allows a maximum of eight parameters to be moved from any location to any other location (including the SAMI Table image and the TBX extension). Each of these eight parameters has an associated "transfer interval". These transfer operations are performed as required by their intervals. The parameters to be transferred and their destinations are specified uniquely for each application.

A contiguous temporary storage area for eight parameters is provided for use as a transfer source/destination. This area is available for use as required by individual applications.

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SAMI Table Manager
A single task, the SAMI Table Manager (STM), is charged with managing the SAMI Table image and the TBX extension. All requests to read or write parameters are delivered to the SAMI Table Manager via operating system messages. Similarly, all responses to parameter read requests are dispatched via operating system messages.

The STM requires a periodic cue from the operating system for the following:

• Processing the "recurring parameter updates" or "update intervals"
• Processing the transfer table
• Processing parameters "update drive" and "stale data" flags

The frequency of this cue is initialized according to the status of channel 1. If the TBX has control of channel 1 and its baud rate is 9600 BPS, the cue will arrive every 12ms: otherwise, one cue will arrive every 24 ms.

The intervals for recurring parameter updates and parameter transfers are expressed in units of cues (12ms or 24ms as appropriate) and decremented with each timer cue. When a counter reaches zero, the corresponding parameter is processed and the counter is re-initialized. Refer to the following sections for a complete description of "update intervals", "transfer intervals" and their relationship with the "scatter" function.

A parameter pointer is needed to facilitate the processing of the "update drive" and "stale data" flags. This pointer indicates the next SAMI Table parameter to be inspected for set flags. This pointer can be monitored by displaying the Parameter "SAMI_PTR" (Parameter 4341) of the TBX Extension.

Parameter Backup to EEPROM
The parameters which are saved in EEPROM are found in the TBX Extension to the SAMI Table. A list of these parameters can be found in Appendix A. Their initial values are stored in firmware.

If an "invalidate" operation is requested, the EEPROM checksum (and hence the contents of the EEPROM memory) will be invalidated. If an "update" operation is requested, the constant values in EEPROM memory will be replaced by the corresponding values in RAM memory. EEPROM operations can be requested through DMS.

Digital Inputs and Outputs
The digital inputs and outputs are accessed via the 80188 I/O address space. Inputs are read by looking at the first four bits of "TBX STATUS" (Parameter 4342). The outputs are controlled by the first four bits of "OX-COMMAND" (Parameter 4343).

TBX Initialization
Upon processor reset, processor hardware and software are set up, i.e.: digital outputs are de-energized & RAM and EEPROM are tested. If the hardware check is successful, then the operating system runs the initialization task.

Initialization Task
Since this is the only task which is created before the operating system is given control, it will run immediately and perform the following:

• Each SAMI channel UART is set to: one start bit, seven data bits, even parity and one stop bit. The speed is set to a default value of 9600 BPS. The interrupts are initialized, cleared, and disabled for each channel. Each channel utilizes an "auto-baud" feature to determine the actual baud rate.
• DOMINO PLUG negotiation and setup is performed via PlugWare. If this operation fails, it will be tried again after a brief delay. The initialization process will not continue until Plug negotiation and setup is successful.
• The tasks which handle the SAMI communications are started.
• The SAMI Table Manager, Update SAMI Data task, Sample Collection task, and DH+ Handler are started. The initialization process will not proceed further until a message is received from the SAME Table Manager indicating that the SAMI table image has been initialized from the drive controller or that such initialization was not required.
• The remaining tasks are started (Periodic Parameter Read Task, Remote I/O Handler, and DIO Handler).

When this task is finished, it cannot run again until processor is reset.

STM Initialization/Start-Up Message
The first message received by the STM is an initialization message. Upon receipt of this message, the STM will acquire and initialize an array in memory to be used for its SAMI table. All parameter values in this table are initialized to zero. The "update" flag for all parameters are set to FALSE.

The EEPROM checksum will be checked. If it is valid, constants for the TBX extension of the SAMI Table will be copied from the EEPROM memory. If the checksum is invalid, the constants will be copied from EPROM memory (a status flag in the TBX extension of the SAMI Table will be set to indicate that EPROM defaults are in use).

A pointer, "SAMI-PTR" (Parameter 4341) used to indicate the next parameter to have its "stale" and "update" flags inspected is initialized according to the initialization mode in use. This pointer is subject to a maximum value defined by the parameter "LAST_SAMI_ADDR" (Parameter 4157).

IMPORTANT: If this parameter is set less than 255, a minimum value of 255 is enforced.

"Long" Initialization Mode
To activate this mode, a parameter in the TBX extension of the SAMI Table named "HIGH_INIT" (Parameter 4194) is set to a non-zero value.

IMPORTANT: When this parameter is non-zero, it is forced to a minimum value of 255. It must have a value less than or equal to "LAST_SAMI_ADDR". The "stale" flags are set for all parameters from 1 through the "HIGH_INIT", except for those which are part of the trend buffers.

The pointer used to indicate the next parameter to have its flags inspected is initialized to parameter 114 (start of the drive's periodic parameter update data). The TBX will proceed by reading all parameters from 114 to 173 (communication type) from the drive controller. When this is complete, the TBX will cause the drive to cease its periodic transmissions to the TBX so that the entire bandwidth of the SAMI channels is available for initialization. When all active parameters (defined by "HIGH_INIT") have been read from the drive controller, the drive's periodic parameter updates will be reactivated (the parameters read earlier, starting at 114, are used for this purpose). At this point, initialization will be completed and the TBX will be in the normal operating mode.

"Short" Initialization Mode
To activate this mode, a parameter in the TBX extension of the SAMI Table named "HIGH_INIT" is set to zero. The "stale" flags are not set for parameters from 1 through 4095. At this point, initialization will be completed and the TBX will be in the normal operating mode.

Data Highway Plus (DH+)
Services
The 3500-TBX Data Highway Plus (DH+) Services will emulate a PLC 2 compatibility mode. The following PCC (Programmable Controller Communications) commands are processed via the DH+:

• Protected Block Data Table Write
• Unprotected Block Data Table Write
• Unprotected Block Data Table Read
• Read Diagnostic Counters
• Reset Diagnostic Counters
• Identify Host and Some Status
• Special TBX services (used by DMS)

DH+ Handler Task/Start-Up Message
The DH+ Handler will receive a start-up message soon after the TBX starts. Upon receipt of the startup message, the DH+ Handler will configure channel A of the DOMINO PLUG for the DH+ mode. The configuration parameters (node address and baud rate) are contained in the start-up message. The DH+ Handler will enter a special mode until TBX initialization is complete. While in this special mode, the DH+ Handler will process only a subset of the normal OS messages and PCC commands. A flag in the " TBX_STATUS" Parameter will indicate that the TBX is in the initialization mode. When the DH+ Handler receives a message indicating that the TBX has completed initialization, it enters a normal operating mode.

PLUG / Interrupt Interface
The PLUG Interrupt Handler will send a message to the DH+ Handler when a link command is waiting to be processed. One such message is sent for each interrupt.

RIO Services
Remote Input/Output (RIO) Services
Only the Discrete I/O services of RIO are used; all other services are disregarded.

Conversion tables, known as the "scatter table" and the "gather table" are required for the processing of the Discrete I/O Update services.

The "scatter table" contains the data necessary for converting the Output Image addresses to SAMI Table addresses. For each parameter represented in the "scatter table", there is an associated SAMI table address. The values in the "scatter table" are initialized to zero. Actual values are downloaded via the DH+ services or retrieved from EEPROM. A SAMI table address of zero in the "scatter table" indicates that the corresponding parameter in the RIO output image should not be copied to the SAMI Table.

The "gather table" contains the data necessary for converting the SAMI table addresses to Input Image addresses. For each parameter represented in the "gather table" there is an associated SAMI Table address. The values in the "gather table" are initialized to zero. Actual values are downloaded via the DH+ services or retrieved from the EEPROM. A SAMI Table address of zero in the "gather table" indicates that the corresponding parameter in the RIO input image is not to be processed.

The "scatter table" and the "gather table" are unique to the TBX and are therefore stored in the TBX extension of the SAMI Table.

RIO Handler Task
Start-Up Message
The RIO Handler will not receive a start-up message until initialization is complete. The start up message contains no parameters. The RIO handler task will configure Channel B of the DOMINO PLUG for the RIO Adapter mode when its configuration parameters have been received from the SAMI Table Manager (STM). When the RIO handler has received a valid set of station parameters, the channel will be placed on line. Next, a buffer will be acquired for temporary storage of the "output image" during normal operation. Finally, a message will be formatted and sent to the STM for the purpose of requesting the current "input image". This message will be used repeatedly during normal operations. The RIO Handler will then enter the normal operating mode.

Stop Message
This message, which may be received during start-up or normal operating modes, causes the RIO channel to release all outstanding PLUG resources and place the RIO channel off-line. The STOP message will be returned to the requesting task with the appropriate status. If the STOP operation was successful, the RIO Handler will enter a "wait" mode until it is terminated.

PLUG / Interrupt Interface
The PLUG interrupt handler will send a message to the RIO Handler when a Discrete I/O command is waiting to be processed. One such message is sent for each interrupt.

"Read RIO Inputs" (i.e.: "Gather" Inputs) Message
This message, which originates at the RIO Handler, is requesting the values for the RIO inputs. The "Gather table" is used to convert the SAMI table addresses to Input Image addresses. Gather table entries are re-validated only when an RIO reset, plug reset or TBX reset is received. If a parameter ' index value is out of range, a status flag in the TBX extension of the SAMI Table will be set to indicate that a configuration error has been detected. A Gather table index of zero for a parameter indicates that it is not implemented. The necessary parameters are then retrieved from the TBX SAMI Table and placed in the message. The message is then returned to the RIO Handler.

When a parameter is "gathered", the TBX must determine if it will be automatically updated by the drive controller through its index/interval table (parameters 114-129). If not, the "stale" flag will beset for that parameter.

"Write RIO Outputs" (i.e.: "Scatter Outputs") Message
This message, which originates at the RIO Handler, contains new values of the RIO outputs. The "Scatter table" is used to convert the Output Image addresses to SAMI Table addresses. Scatter table entries are re-validated only when an RIO reset, plug reset or TBX reset is received. If a parameter index is zero, the entry is ignored. If the index is out of range, or if a non-zero index has an invalid interval value, a status flag in the TBX extension of the SAMI Table will be set to indicate that a configuration error has been detected. The necessary parameter values are then moved to the TBX SAMI Table. No response message is needed.

In addition to validating the Scatter table, the incoming message contains a status word which indicates whether the image is valid. If the image in the message is invalid, all zeros will be scattered and a status flag in the TBX extension of the SAMI Table will be set to indicate that a bad RIO image has been received.

RIO Operation
Baud Rate Selection
The minimum number of TBX racks per remote 1/O link must be followed to allow optimum TBX performance. If fewer racks are put on the link, TBX performance will be sacrificed.

The minimum numbers of racks are:

Output Image Processing
The remote 1/O algorithm for processing the output image is optimized so that changing data has precedence over unchanging data. This means that if only one output word's data is changing, only that parameter will be transmitted to the drive.

Additionally, every 25th parameter transmission will be of an unchanging parameter. This ensures that all parameters are periodically updated in the drive.

Input Image Processing
The input image to the PLC is updated after the processing of every second output image. For example: if the remote 1/O update time (the time between new output images) is 25 mSec., the input image will be updated every 50 mSec. If all scatter indexes are zero (no output image data sent to the drive), the input image will not be updated. That is, the input image processing is linked directly to the output image processing. Simply put, a scatter table must be defined before a gather table will be processed.

SAMI Protocol Transmit and Receive
SAMI Protocol Receive Handler
The SAMI Protocol Receive Handler (SPRH) handles all SAME messages from the drive controller. The SPRH for both SAMI channels are identical. If SPRH fails to receive a SAMI message from channel 1 for 3 seconds, channel 1 is assumed to be offline, and bit 8 of TBX-Status (parameter 4342) will be set.

"Write SAMI Parameter" Command
When a "write parameter" SAME command (for addresses 1-255) is received from the drive controller, the parameter's address and new value are placed in an operating system message. This message is then sent directly to the STM for updating.

"112" and "113" SAMI Commands
When a "112" or "113" SAMI command is received by the SPRH, it indicates that the SPXH task is conducting an "extended address write" operation or a "parameter read" operation. The address and data fields from these commands are placed into an operating system message and sent to the SPXH for processing.

"Update Data" Check:
When a "Write SAMI Parameter" message is received, the STM will check if an "update data" request is pending. If there is such a request pending, and the data received in the "Write SAMI Parameter" message is among the requested parameters, it will be saved in a special buffer. When the "update data" is complete, the "Write SAMI Parameters" will be processed.

SAMI Protocol Transmit Handler
The SAMI Protocol Transmit Handler (SPXH) handles parameter read and write requests from the SAMI Table Manager. The SPXH for both SAMI channels' are identical.

When this task is started, it will execute an "auto-baud" algorithm to determine the speed of each SAMI channel. Once the proper speed has been determined, the baud rate will not be changed.

Communications loss may be detected by all operations which require a handshake or other response from the drive controller. If three consecutive communication failures are detected for a SAMI channel, then its "off line" flag will be set in TBX extension of the SAMI Table. That flag will remain set until three consecutive communication successes are registered for that channel. Once set, a SANE channel's "off line" flag will remain set for a minimum of 2 seconds.

"Write (Drive) Parameter Short" Message
This message contains a parameter address and a new value to be sent to the drive controller. The address must be between 1 and 255. A standard SAMI write command is sent to the drive controller.

"Write (Drive) Parameter Long" Message
This message contains a parameter address and a new value to be sent to the drive controller.

A SAMI protocol "extended write" sequence is required. The SPXH will send the "112" message with the parameter address to the drive controller and wait for the handshake message from the SPRH. If no handshake is received, the operation has failed. If the handshake was received successfully, the "113" message with the value is sent to the drive controller and a "Write (Drive) Parameter Operation Complete" message is sent to the STM.

If the acknowledge mode is enabled (communication type parameter 173 does not equal 0) a SAMI protocol "extended write w/acknowledge" sequence is required. The sequence is as in the previous paragraph except that following transmission of the "113" message with the data, the TBX must wait for an acknowledge message from the drive controller (via the SPRH). If no acknowledge or "negative acknowledge" is received, the operation has failed. Otherwise, a "Write (Drive) Parameter Operation Complete" message is sent to the STM.

"Read (Drive) Parameter Request" Message
This message contains the address of a parameter to be read from the drive controller.
The SPXH will send the "112" message with the parameter address to the drive controller and wait for the response message from the SPRH. If no response message is received, the operation has failed. If the response message is received, a "Write (TBX) Parameter" message with the new value is sent to the STM.

Transfer Table processing
The microprocessor uses SAMI channel 2 to transmit parameters which have associated "update intervals". Any bandwidth remaining after the "update intervals" have been serviced is used to process parameters "stale" and "update" flags. Transfer table processing cannot use more than 10% of channel 2's bandwidth. When the periodic timer cue is received, the transfer table is processed. All entries are revalidated upon receipt of each cue. The following table summarizes the validation:

All intervals of the active entries in the transfer table are decremented. Any parameter whose counter is decremented to zero must be processed by moving the value at the source parameter address to the destination parameter address. After a parameter is transferred, its counter is re-initialized to its transfer interval.

When a parameter is "transferred", TBX must determine if its source address will be automatically updated by the drive controller. If not, the "stale" flag will be set for that parameter address. Also, the TBX must determine if the drive controller will be updated automatically with the value at the destination address (via the "update interval" mechanism). If not, the "update" flag must be set for that parameter address.

Transfer Intervals
The intervals from the "transfer" tables must be evaluated as a set. The TBX will not accept a set of interval times which would use up more than 10% of the communication channel. The minimum update interval for a parameter is a function of the total number of parameters scheduled for a recurring update. The following table shows this relationship for eight possible transfer intervals:

If the intervals are invalid as set, a status flag in "TBX STATUS" (Parameter 4342, Bit 14) will be set to indicate that a configuration error has been detected. No periodic parameter updates will be processed until the error has been corrected.

Based on the above validations, the amount of time available to handle other SAMI transactions is calculated. The result can be: 100% of time available (i.e.: no periodic parameter updates implemented), 90% of time available (i.e.: maximum time spent doing periodic updates), or some fraction of time available.

SAMI Drive Channel 2
The microprocessor has exclusive use of SAMI drive channel 2. It is used to process parameters "stale" and "update" flags. Channel 2 also handles the following special services, which are described in subsequent sections:

• Debug Write
• Periodic Parameter Read requests
• Data Sampling (DMS Monitor Function)

"Debug Write (Drive) Parameter" Message
This message contains the address of a parameter and data to be sent to the drive controller. The address is in the "physical" format (i.e.: "regular" parameter address = 2 (Physical address) + 4096). This operation is used for diagnostic operations only and has a protocol considerably different from the "write parameter long" operation previously described. The task which requested this operation will be waiting for a response. Accordingly, the SPXH task will respond to a debug write request, even if it is unsuccessful. In other words, debug write requires an acknowledge or negative acknowledge handshake between the requesting task and the SPXH. The SPXH will send the physical address to location 216 in the drive controller's SAMI Table. Next, a "112" message with the parameter address field set to 216 is sent to the drive controller and the SPXH waits for the response message from the SPRH. If no response message is received, the operation has failed. If the response message is received, but the contents of location 216 is not equal to the requested physical address, the operation has failed.

If the proper value was placed in 216 by the drive controller, the specified data is sent to location 217 in the drive controller's SAMI Table. A "112" message with the parameter address field set to the specified parameter (in "regular" not "physical" format) is sent to the drive controller and the SPXH waits for the response message from the SPRH. If no response message is received, the operation has failed. If the response message is received, but the specified data was not written to the specified parameter address, the operation has failed. Otherwise, the operation is assumed to have completed successfully.

Finally, the request message is returned to the originating task with the appropriate status.

"Periodic Parameter Read" Task
This task, which runs at 15 second intervals, will request that certain critical parameters be read from the drive controller. The parameters to be read are those which represent the drive controller's periodic update tables (parameters 114 through 129 and 134 through 151) plus the communications type (parameter 173). One parameter will be read for each activation of this task. The read requests will be on SAMI channel 2. These read requests receive priority handling.

There are two purposes for this task:

• It helps ensure that the TBX copies of the parameters listed above are synchronization with the drive controller.
• It ensures that there is regular, two way traffic on the SAMI channels. This allows breaks in communication to be detected by the TBX when there is no other traffic.

If an error occurs on a "periodic parameter read" on channel 2, the channel 2 comm loss (bit 9) bit is set in TBX Status (parameter 4342).

"SampleData" Task
The data collection task handles several message types, described in the following paragraphs. The TBX maintains a "sample clock" for use by this feature. This clock is simply a long word counter in units of milliseconds. It is incremented by 12 every 12 milliseconds. This clock will be used as a "time stamp" for the collected samples.

Start Parameter Collection Message: This message originates at the DH+ Handler from the DMS software. Upon its receipt, the SAM task will perform the following validations:

• Is another sampling operation is already is progress?
• Are the requested sampling intervals invalid?
• Are any of the requested parameters out of range?

If any of the above error conditions is detected, the message is returned to the DH+ Handler with an error status.

If the message is valid, it is returned to the DH+ Handler with a success status and the SAM task will start the sampling operation. Two buffers are acquired. One buffer is used to retrieve set of samples from the STM at the specified intervals. The second buffer is used to hold the sample sets for I second (these will be sent to the DH+ Handler for transmission to the requesting station). Finally, the first sample request is sent to the STM. The SAM task will attempt to issue the first sample request as closely as possible to a one second boundary on the sample clock.

Stop Parameter Collection Message
This message originates at the DH+ Handler. Upon its receipt, the SAM task will perform the following validations:

• Is no sampling operation in progress?
• Is the station requesting the STOP different from the station which started the sampling operation?

If any of the above error conditions is detected, the message is returned to the DH+ Handler with an error status.

If the message is valid, it is returned to the DH+ Handler with a success status and the SAM task will stop the sampling operation. The outstanding buffer used to get a set .of samples from the STM is retrieved and released. The buffer is used to hold the sample sets for I second is also released. Finally, DH+ messages that have not been acknowledged for sample transmissions will be deleted.

Force Stop Parameter Collection Message
This message may be received from several different tasks under different circumstances. For example, if the DH+ channel is off-line, this message will be issued to halt the sampling operation. If a sampling operation is in progress, the sampling operation will be stopped unconditionally. The outstanding buffer used to get a set of samples from the STM is retrieved and released. The buffer is used to hold the sample sets for 1 second is also released. Finally, DH+ messages that have not been acknowledged for sample transmissions will be deleted. The incoming message is not returned to the originating task.

Response to "Read Samples" Message
When a set of samples is received from the STM, the SAM task must transfer them to the other buffer which was acquired when the operation began. If the current set of samples is the first to be placed in that buffer, various parameters, including the sample clock "time stamp" must be initialized. If the current set of samples is the last set which will fit in that buffer, it will be forwarded to the DH+ Handler for transmission to the requesting DH+ station and a new buffer must be acquired. Finally, a new request for a set of samples is sent to the STM.

Set Sample Clock Message
This message will cause the sample collection clock to be re-initialized to the specified value.

Digital I/O Handler Task
Start-Up Message
The DIO Handler will not receive a start-up message until TBX leaves the initialization mode. The start up message contains no parameters.

DIO Processing
Upon activation, the DID Handler will read the inputs and send their values to the STM. The response message from the STM will contain the new values for the outputs. After updating the outputs, the task will be dormant for another 24 ms.

TBX diagnostics and Monitoring
Power-up Tests
Whenever the TBX processor resets, the RAM and EPROM tests will be executed.

Watchdog Handler
The TBX watchdog time-out circuit must be retriggered by software to prevent processor reset. This is done in a high priority task which is scheduled to run every 12ms.

Plug Status Monitoring
The on-line, off-line status of both plug channels is inspected at one second intervals. This is done by inspecting the mode of the LED for each channel. If the LED is not in the "solid green" mode, the channel is assumed to be off line.

In the case of the DH+ channel, a message will be issued to stop the parameter sampling operation (if one is in progress). A status flag will be set in the TBX extension of the SAMI table indicating that the DH+ channel is off-line.

In the case of the RIO channel, a status flag will be set in the TBX extension of the SAMI table indicating that the RIO channel is off-line. Furthermore, a message will be sent to the STM task which will cause an output image consisting of zeros to be "scattered". Finally, a status flag will be set in the TBX extension of the SAME table indicating that the RIO output image is bad (i.e.: RIO off line implies bad output image).

"Set / Reset Status or Set Command Flag" Message
Upon receipt of this message, the STM will check if it is a "command" or "status" request.

TBX Status
The specified status flag (located in the unused portion of the digital input parameter) will be set or reset (as requested).

TBX Command Flag Processing
The specified command flag (located in the unused portion of the digital output parameter) will be set with a message. The STM continually monitors the command flags in the TBX extension of the SAMI Table.

Reset TBX Command: This command is always allowed. All maskable interrupts are disabled, causing a "watchdog timer" reset of the processor.

Reset Plug Command: This command is not allowed during initialization mode. This command takes precedent over the DH+ and RIO channel reset commands. A "STOP" message will be sent to both the DH+ and RIO handler tasks. These messages will cause the channels to be placed off-line. When return confirmation is received from the Plug channel handler tasks, they will be "terminated". The Plug will then be reset and reconnected (including renegotiation of parameters). Finally, the Plug channel handler tasks will be restarted, causing the channels to be reinitialized.

Reset DH+ Channel Command
This command is not allowed during initialization mode. A "STOP" message will be sent to the DH+ handler task. This message will cause the channel to be placed off line. When return confirmation is received from the DH+ handler task, it will be "terminated". Finally, the DH+ handler task will be restarted, causing the channel to be reinitialized.

Reset RIO Channel Command
This command is not allowed during initialization mode. A "STOP" message will be sent to the RIO handler task. This message will cause the channel to be placed off line. When return confirmation is received from the RIO-handler task, it will be "terminated". Finally, the RIO handler task will be restarted, causing the channel to be reinitialized.

Appendix

A. TBX Parameter Table Extension
The TBX uses a set of parameters, some of which are preset at the factory, to select and control operation.

The SCATTER INTERVAL is not used in this implementation.
If SCATTER INDEX is zero, the parameter is not scattered.

The GATHER INTERVAL is not used in this implementation.
If GATHER INDEX is 0, the parameter is not gathered.

If TRANSFER INTERVAL is 0, the parameter is not transferred.

TRANSFER INTERVAL is 24 mSec at 4800 baud and 12 mSec at 9600 baud.

The SOURCE INDEX and DESTINATION INDEX may be any parameter address including the TBX extensions.

-1 =NOT USED
Address is decimal Rack Number, NOT Octal Address.

-1 = NOT USED
0 = 57.6k
1 = 115.2k
2 = 230.4k

-1 = NOT USED
0 = 1/4 Rack
1 = 1/2 Rack
2 = 3/4 Rack
3 = Full Rack

-1 = NOT USED
0 = NOT Last Module Group in Logical Rack or Full Rack
1 = Last Module Group in Logical Rack

-1 = NOT USED
0 = GRP 1 (MOD GRP 0)
1 = GRP 2 (MOD GRP 2)
2 = GRP 3 (MOD GRP 4)
3 = GRP 4 (MOD GRP 6)

This is the Last Parameter defined by the Drive Firmware.

This is the number of Parameters the TBX must read from the drive before DH+ is active and TBX initialization is complete.

This is the current SAMI Table Parameter that the TBX Same Table Manager is processing.

The TRANSFER BUFFERS are general purpose buffers for use by applications.

**End of Document**
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