7
All Rights Reserved. Copyright © 2015, Yokogawa Electric Corporation
TI 34M06Z43-01E
4.
Checking Special Registers and Special Relays
4.1
What are Special Registers and Special Relays?
Special registers and specials relays are registers and relays that have specific functions relating
to, say, the internal state and errors of the FA-M3. When an error is detected and logged in the
system log, the self-diagnosis result may also be saved in special registers (Z) in the sequence
CPU module.
In addition, a special relay (M) corresponding to the error is set. This special relay may be
checked in a ladder program for error detection purposes. Refer to the following table for
mapping error messages to special registers and special relays.
Mapping Failures to Special Registers and Special Relays
Severity of
Failure
Failure Classification
LED
Indicators
Special Relay
that Turns On
Special
Registers
Storing Error
Code
Major failure
System error
All LEDs are
off.
－
－
Moderate
failure
Self-diagnosis
error
Startup error
ERR is lit
M193
Z017 to Z019
Boot mode error
SPU error
memory error
Invalid instruction
found
Program error
Battery error or memory check
pattern error
M194
－
Moderate
failure or
minor failure
(user-defined)
Instruction
processing
error
Subroutine error
ERR is lit if
defined as
moderate
failure;
ALM is lit if
defined as
minor failure
M201
Z022 to Z024
Interrupt error
Instruction error
Macro instruction
error
I/O comparison error
M202
Z027 to Z029
I/O module error
M203
Z033 to Z040
Scan timeout
M204
－
Sensor CB scan timeout
M212
－
Subunit communication error
M210
Z089 to Z096
Minor failure
Momentary power failure
ALM is lit
M195
－
Inter-CPU communication error
M196
－
Subunit transmitter switching has
occurred
M211
Z089 to Z096
FA link (1 to 8) error
M0273-M0368
M0369-M0480
M8321-M8432
M8433-M8544
M8545-M8656
M8657-M8768
M8769-M8880
M8881-M8992
－
