Delta DVP-ES2/EX2/SS2/SA2/SX2/SE manual Applications of Special M Relays and D Registers

2. Programming Concepts

2.16 Applications of Special M Relays and D Registers

Function Group PLC Operation Flag

Number M1000~M1003

Contents:

These relays provide information of PLC operation in RUN status.

M1000:

NO contact for monitoring PLC status. M1000 remains “ON” when PLC is running.

	M1000		PLC is running
		Y0
Normally ON contact
in PLC RUN status			Keeps being ON

M1001:

NC contact for monitoring PLC status. M1001 remains “OFF” when PLC is running.

M1002:

Enables single positive pulse for the first scan when PLC RUN is activated. Used to initialize registers, ouptuts, or counters when RUN is executed..

M1003:

Enables single negative pulse for the first scan when PLC RUN is activated. Used to initialize registers, ouptuts, or counters when RUN is executed.

PLC RUN

M1000

M1001

M1002

M1003

scan time

Function Group Monitor Timer

Number D1000

Contents:

1.Monitor timer is used for moitoring PLC scan time. When the scan time exceeds the set value (SV) in the monitor timer, the red ERROR LED will be ON and all outputs will be “OFF”.

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