Rockwell Automation 1771-DA,D17716.5.13 U MNL 1771-DA ASCII I/O MODULE - Manual (Page 163)

Troubleshooting
Chapter 7
7Ć4
Table 6.B
Troubleshooting Chart
Indication Description Recommended Action
FAULT
BUFFER FULL
CHANNEL ACTIVE
Normal operation
FAULT
BUFFER FULL
CHANNEL ACTIVE
ASCII characters are not transferred
but all LEDs give normal indication.
1. Check for invalid initialization data
(SW1=X4XX). (X = any hex value)
2. Check parity setting on ASCII
device with setting of IW1(14,15).
FAULT
BUFFER FULL
CHANNEL ACTIVE
Hardware failure in module. Return module for repair
FAULT
BUFFER FULL
CHANNEL ACTIVE
Input buffer full. Loss of spillover
data if control lines are not used.
1. Check for loss of data.
2. Increase ratio or input buffer to
output buffer in IW3(00Ć02).
3. Increase block transfer rate by
transferring multiple strings in each
transfer. Set IW2(17)=1 and modify
your program.
4. Decrease communication rate from
ASCII device.
FAULT
BUFFER FULL
CHANNEL ACTIVE
ASCII characters are transferred
but all LEDS are OFF.
1. Check programming plugs for correct
placement . See section titled "Setting
the Module's Programming Plugs",
P. 2Ć11
2. If a multiple port ASCII device is
being used, check for use of correct
port.
3. Check 1772ĆTC Cable.
= off
= on
During installation and start-up you will find the codes displayed in status
word one (SW1) very helpful. You can observe them when you display
the read block transfer file in your program’s BLOCK XFER READ
instruction. Typical codes for correct operation (Table 6.C), buffer status
(Table 6.D), and fault status (Table 6.E) are shown on the following
pages.
How You Interpret Codes in
Status Word One