Manual

Troubleshooting
Chapter 7
78
When the PM module detects a condition, it immediately generates the
corresponding message code. You can display diagnostic message codes
with an optional display device connected to output modules in these
locations in chassis A and B:
module group 5, slot 1 (8-bit binary code)
module group 3, slot 1, bit 2 (9
th
bit for micro-inch)
When using micro-inch mode, diagnostic diagnostic message codes are
9-digit binary (3-digit hex) rather than 8-digit binary (2-digit hex) for
other diagnostic message codes. The most significant bit (bit 9) indicates
a micro-inch code. When set, 2-digit hex codes XX become 3-digit hex
codes 1XX for micro-inch.
You can display diagnostic message codes in 9-digit binary, or use an
optional binary-to-hex converter and display diagnostic message codes in
easy-to-read hexadecimal notation. No programming is required. Just
install output modules in those locations and connect display devices
(Figures 6.13 and Figures 6.14).
You can also view diagnostic message codes with an Allen-Bradley
programming or display terminal using the data monitor feature:
If using this
processor Use this device
PLC2 family Industrial T erminal (1770T3)
Handheld T erminal (1770T1 1)
PLC3 family Industrial T erminal (1770T4)
Data access panel on the front of the processor or
1784T45, T47, or T50 Programming T
erminal
PLC5 family 1784T45 ,T47, or T50 Programming T erminal
PLC5/250
1784T45, T47, or T50 Programming T erminal
Display of Diagnostic Message
Codes