User guide

Health Status
890 USE 108 00 August 2001 207
Status Information
Structure of
Status
Information
Three words contain health and communication information on the installed I/O
modules.
If monitored with the Stat block, they are found in Words 182 through 184. This
means that, at a minimum, the length of the Stat block must be 184.
Words 16 ... 181
Not Used
Words 16 through 181 are not used.
Word 182
Health Status
Word 182 increments each time a module becomes bad. After a module becomes
bad, this counter does not increment again until the module becomes good and then
bad again.
If the bit is ‘1", then this condition is true or ON.
The following figure shows Word 182.
Bit 1 is set if all modules are healthy. Bits 9 ... 16 are a counter that increments if a
module is unhealthy. It will roll over at a count of 255.
Word 183
I/O Error Counter
This error counter is similar to that for a good/bad module. This word, however,
increments every scan that a module remains in the bad state.
Word 184
PAB Bus Retry
Counter
Diagnostics are performed on the communications through the bus. This word
should normally be all zeros. If after 5 retires, a bus error is still detected, the
controller will stop and error code 10 will be displayed. An error rolls over while
running. If the retires are less than 5, no bus error is detected.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
“Module Went
Unhealthy” Counter Used
All modules healthy
Not Used