Handling Of Operation Error Flag; Handling Functions Of Extension Flag - Mitsubishi Electric FX3G SERIES Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
6.5.3

Handling of operation error flag

When there is an error in the applied instruction configuration, target device or target device number range and an
error occurs while operation is executed, the following flag turns ON and the error information is stored.
1. Operation error
Error flag
M8067
• When an operation error has occurred, M8067 turns ON and D8067 stores the operation error code number.
• In the FX /FX
3U
When the error occurrence step number is up to 32767, the error occurrence step can be checked also in D8069
(16 bits).
• In the FX PLC, D8069 stores the error occurrence step number.
3G
• If another error occurs in another step, the stored data is updated in turn to the error code and step number of the
new error. (These devices are set to OFF when errors are cleared.)
• When the PLC mode switches from STOP to RUN, these devices are cleared instantaneously, and then set to ON
again if errors have not been cleared.
2. Operation error latch
Error flag
M8068
• When an operation error has occurred, M8068 turns ON.
• In the FX /FX
3U
When the error occurrence step number is up to 32767, the error occurrence step can be checked also in D8068
(16 bits).
• In the FX PLC, D8068 stores the error occurrence step number.
3G
• Even if another error has occurred in another step, the stored data is not updated, and remains held until these
devices are forcibly reset or until the power turns OFF.
• When the error occurrence step is up to the 32767th step, the error occurrence step can be checked in D8068 (16
bits).
6.5.4

Handling functions of extension flag

In some applied instructions, the function can be extended by combining a specific special auxiliary relay determined
for each applied instruction. An example is explained below.
- When X000 turns ON, this instruction exchanges the
contents of D10 and D11 with each other.
- If M8160 has been driven before the XCH instruction and
the source and destination of the XCH instruction are
specified to the same device, high-order 8 bits and low-
order 8 bits are exchanged with each other inside the
device.
- For returning this XCH instruction to the normal XCH
instruction, it is necessary to set M8160 to OFF.
When using an instruction requiring the function extension flag in an interrupt program, program DI instruction (for
disabling interrupt) before driving the function extension flag, and program EI instruction (for enabling interrupt) after
turning OFF the function extension flag.
176
Error code storange device
D8067
PLCs, D8315 and D8314 (32 bits in total) store the step number in which the error has occurred.
3UC
Error code storange device
−
PLCs, D8313 and D8312 (32 bits in total) store the step number in which the error has occurred.
3UC
6 What to Understand before Programming
6.5 General Rules for Applied Instructions
Error detected step number storange device
FX /FX PLC
3U 3UC
D8315, D8314, D8069
Error detected step number storange device
FX /FX PLC
3U 3UC
D8315, D8314, D8068
X000
X000
M8160
M8160
FX PLC
3G
D8069
FX PLC
3G
D8068
FNC 17
D10 D11
XCHP
Function extension flag
for the XCH instruction
FNC 17
D10 D10
XCHP
Same number