Quick Reference To Status And Control Bits; Status Bits; Control Bits - Allen-Bradley 1747-SN User Manual

5–22 RIO Block Transfer
Quick Reference to Status
and Control Bits
Publication 1747 6.6 - July 1996
The tables below provide a quick reference for block transfer status
and control bits. In the tables, x = the block transfer file.

Status Bits

This Bit: Is Set:
Enable Waiting EW - upon the scanner's first detection of EN being set. The EW
M1:e.x00/10 bit gets reset when the EN flag resets.
Error ER - M1:e.x00/12 when the scanner detects that the block transfer failed. The
ER bit is reset when the EN flag resets.
Done DN - M1:e.x00/13 at completion of the block transfer, if the data is valid. The DN
bit is reset when the EN flag resets.
Start ST - M1:e.x00/14 when the scanner schedule" the BT for the adapter. The
data transfers may not start for some time. The ST bit is
reset when the EN flag resets.

Control Bits

This Bit: Is Set:
Read Write RW - by your SLC control program. A 0 indicates a write operation;
M0:e.x00/7 a 1 indicates a read operation.
Timeout TO - M0:e.x00/8 if you leave the timeout bit reset, the scanner repeatedly tries
to send a block transfer request to an unresponsive module
for four seconds before setting the ER bit.
if you set the TO bit through your SLC program the scanner
attempts to cancel the BT request.
Enable EN - by your SLC control program to initiate a BT request.
M0:e.x00/15