Rockwell Automation 6008-SV2R VMEbus remote I/O Scanner - Manual (Page 79)

Chapter
Operating in SVĆCompatible Mode
5
5Ć28
Byte
offset:
Parameter: Description:
107 module address The module address is the address of the I/O modules that is to
receive the block data.
The module address is the address of the I/O module that is to
receive the block data. It contains the rack (0-15), group (0-7),
and slot (0 or 1) numbers of the I/O module. See Figure 5.14.
109 blockĆtransfer tag number The blockĆtransfer tag number is an 8Ćbit integer that uniquely
identifies each blockĆtransfer. The scanner writes a value 0-41 to
the blockĆtransfer request tag number in the control/status area.
Values greater than 41 are reserved. If you write a reserved value
to this field, the scanner writes an illegal confirmation error (16) in
the confirmation status byte.
This tag is returned with the status when the block transfer is
complete so the VME master processor can match the block
transfer status with the request.
11F length of data The length of data byte is an 8Ćbit value that specifies the number
of 16Ćbit words (0-64 decimal) to be written to the target
I/O module.
Use the value 0 to let the I/O module determine how many words
the scanner can write. When the blockĆtransfer completes, the 0 is
replaced by the actual number of words written.
Values greater than 64 are reserved. If you write a reserved value
to this field, the scanner writes an illegal confirmation error (16) in
the confirmation status byte.
120 BT data The BT data is the set of data words (0-64) sent to the target I/O
module. The BT data block ends at offset (length of data - 1).
Figure 5.14
Structure of the address byte
0 = terminals 00-07
1 = terminals 10-17
6 5 4 3 2 1 0 7
Your code for the BT WRITE command should included these tasks:
1. get the semaphore
2. set up the control status area
3. send the command interrupt
4. wait for the result
(either poll for confirmation status or wait for an interrupt)
5. clear the semaphore
coding sequence