Tag Archives: mitsubishi plc special relays

The values of M8004, M8037, M8061, M8066 in PLC program?

M8004 is an error alarm. When an error occurs in the PLC, such as power failure, hardware error, parameter, etc., M8004 is ON.
M8034 is all outputs in hexadecimal. When M8034 is ON, all outputs Y are stopped.
M8037 is forced STOP. When M8037 is ON, the status of the PLC is forced to STOP.
M8061 is a hardware error alarm.
M8066 is a loop error alarm.

What is the difference between the usage of m8004 in fx1n and the usage of m8004 in fx3ga?

How to use M8004 in Mitsubishi plc,

The PLC may report an error when an error occurs in the plc’s instruction. We first enter a correct command: input LD X0.

Connect an output component Y0 to X0. This instruction is correct. In order to learn about the M8004 alarm, we can add another wrong command.

Enter the command returned by a subroutine in the command: SRET, and then press the OK key.

In order to view the status of the M8004, we use the M8004 as a contact in the program to control the output of Y4.

After the program is written, press the Convert button to compile the program, then press the Simulate Test button to simulate the program.

When the program is transferred, you can see that the test window has indicated an error, and the auxiliary relay M8004 has also been activated.

How to understand M8000 m8001 m8002 in MITSUBISHI PLC

M8000– runs normal open contacts and PLC runs ON all the time.

M8001– runs normal closed contacts and PLC runs OFF all the time.

M8002– initializes the pulse normally open contact. PLC runs ON with a scan cycle.

M8003– initializes pulse normally closed contacts. PLC runs OFF with a scan cycle.

this is Operation sequence diagram of special relay