Mode Detection
- Last UpdatedJul 08, 2025
- 1 minute read
The PLC mode is determined by two things. Firstly, the physical key position in the PLC; and secondly, when in REMOTE mode, whether or not the PLC has been set to RUN mode or PROGRAM mode. This state is represented in the PLC by a numeric value that can be queried.
The following table sets out the different values and the corresponding PLC mode:
|
Mode Value |
Key Position |
Mode |
|
0x1060 |
RUN |
RUN |
|
0x3060 |
REMOTE |
RUN |
|
0x3070 |
REMOTE |
PROGRAM |
|
0x2070 |
PROGRAM |
PROGRAM |
These values can be used to set up a status tag to determine what mode the PLC is currently in, as shown below.
|
Status Tag |
Configuration Description |
|
@Mode<0x2000 |
Key position in RUN |
|
@Mode>0x3000 |
Key position in REMOTE |
|
@Mode!&0x1000 |
Key position in PROGRAM |
|
@Mode!&0x10 |
PLC in RUN mode |
|
@Mode&0x10 |
PLC in PROGRAM mode |
Hence the unit can be taken offline or back online depending on the key position and the current mode of the PLC to display #COM for the points on this unit.