CONTREX CX-1200 - Manual (Page 191)

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PLC MONITOR
Use the PLC Monitor screens to monitor the state of all the PLC operands. Pages 2, 3 and 4 of the screens
display the PLC bits in sequential order. Press the “help” key on each line to view the names for each bit.
The Help screen will highlight the bits that are active.
Page 1 of the PLC Monitor screens displays the parameters that select the PLC bits and monitor the PLC.
Use the Control Parameters Bit ; PLC Monitor 1 (CP-405) and PLC Monitor 2 (CP-406) to select a bit. The
name and value of the bit that you choose is displayed in the corresponding Monitor Parameters ; PLC Mon 1
Val (MP-108) and PLC Mon 2 Val (MP-109). The default names for these Monitor Parameters (PLC Mon
1 Val and PLC Mon 2 Val) are replaced by the name and value of the PLC Bits selected in PLC Monitor 1
(CP-405) and PLC Monitor 2 (CP-406). You can also use the Code key when you are in any parameter
screen to display the PLC Bit names and values of PLC Mon 1 Val (MP-108) or PLC Mon 2 Val (MP-109).
You can also customize the Status screen to display them.
DI Set (CP-403) simulates an active low condition on one of the digital inputs, DI_8 through DI_15, without
having to physically short the input connector to common. Enter a number with a “1” in the bit location
corresponding to the digital input you want to force active. The action will be reflected in PLC 15-8 (MP-
110), which displays the bit values for the digital inputs DI_8 through DI_15.
PLC Bit Set (CP-407) and PLC Bit Clear (CP-408) allow you to force a PLC Bit “On” (1) or “Off” (0). You
can set (or clear) one of the status bits (contacts), PLC Bits 8-95, but you can not control a PLC Bit (coil)
that is controlled by the PLC program (with the “OUT” command). Enter the number of the PLC Bit that you
want to set (1) into PLC Bit Set (CP-407) and the number that you want to clear (0) into PLC Bit Clear (CP-
408). When you are done testing, enter a “0” into PLC Bit Set (CP-407) and PLC Bit Clear (CP-408) .
They will automatically default back to PLC Bits 3 (One) and 2 (Zero ), respectively.