Rockwell Automation 1747-ASB Remote I/O Adapter - Manual (Page 93)

Publication 1747-UM006B-EN-P - June 2003
Start-Up and Operation 6-7
RIO Discrete Transfers To Block Transfer Chassis Slots
Discrete output image data received by the 1747-ASB module for a
block transfer slot is ignored by the 1747-ASB module.
Discrete input image data from the 1747-ASB module for block
transfer slots may be non-zero.
RIO Block Transfers To Discrete Chassis Slots
RIO block transfers to the 1747-ASB module for discrete slots are
ignored by the 1747-ASB module.
Invalid Length RIO Block Transfers
An invalid length RIO block transfer occurs when:
1. An RIO block transfer to an I/O module controlled by the
1747-ASB module is larger than the I/O module's image size.
For example, if an eight word RIO block transfer is made to a
I/O module with an image size of four words, an invalid length
RIO block transfer has occurred.
2. An RIO block transfer write is made to a slot that contains a
module that only has input image.
3. An RIO block transfer read is made from a slot that contains a
module that only has output image.
4. Invalid length block transfers are ignored by the 1747-ASB
module.
Testing the 1747-ASB
Module The 1747-ASB module can be tested prior to beginning normal
operation by following the procedure provided below:
1. Install the 1747-ASB module and I/O modules into the remote
chassis, and if necessary, remote expansion chassis. Make sure
the PLC or SLC processor is in the program mode.
IMPORTANT
Performing an RIO block transfer to a discrete
chassis slot which has an output module in it may
cause outputs on that module to turn on.