Class Error Descriptions; Class 1 Error Descriptions; Class 2 Error Descriptions; Class 3 Error Descriptions - ABB AC 31 Technical Manual

4.3. Class error descriptions:

Class 1 error descriptions

Flash EPROM checksum error

Class 2 error descriptions

Defective RAM (user program or
data memory)
Too many simultaneous timers
active on the central unit during
program execution (maximum 42)

Class 3 error descriptions

Unit disconnected
CS 31 bus error (no units
connected to the bus)
Note: If there are only analog units
connected to the CS 31 bus, then
this error could occur when
powering up while the analog units
aren't initialized.
Reason: Analog units have a
lengthy initialization period. They
are recognized thereafter by the
central unit
NCB or NCBR error
Note: one of the CS 31 lines is
defective. Check the red Led status
of the NCB or NCBR to find out
which one is at fault.
Superposed address
Cycle time too short
Page 8-10
Diagnosis
4.3.1. Class 1 error descriptions
Error code in
MW254.00
Dec Hex
- -
4.3.2. Class 2 error descriptions
Error code in
MW254.08
Dec Hex
128 80
D H
255 FF
D H
4.3.3. Class 3 error descriptions
Error code in
MW255.00
Dec Hex
15 0F
D H
16 10
D H
17 11
D H
18 12
D H
200 C8
D H
Info 1 in Info 2 in
MW 254.01 MW 254.02
- -
Info 1 in Info 2 in
MW 254.09 MW 254.10
Memory address -
- -
Info 1 in Info 2 in
MW 255.01 MW 255.02
Unit type Address
- -
- -
- -
Info 3 in
MW 254.03
-
Info 3 in
MW 254.11
-
-
Info 3 in
MW 255.03
-
-
-
-
ABB Control - AC 31
1SBC 260400 R1001-b 06.99