Applies To:
  • CitectSCADA 5.00

If enabled the ABTCP driver will check on startup and every watchtime that a user specified variable in the PLC is changing. If a digital is specified the value must always be on, otherwise the unit is put offline.If an analog is specifed, on startup two consecutive read is peformed with a interval of 1000 ms (specified by [abtcp]timeout), the two reads must get different values before the unit can be put online. At every watchtime if the digital is off or the analog data does not change from the last value read then the driver returns 0x20 (Received data is bad) and puts the unit offline.

The PLC status variable is specified and enabled by the citect.ini variable

status = RawType, BitWidth, UnitType, UnitAddress, UnitCount

RawType is 0,1,4 and 8 for Digital,Int,Long and Byte respectively
BitWidth is 1,16,32 and 8 for Digital,Int,Long and Byte respectively
for UnitType see variable specfication .dbf files.
UnitAddress is the item number or bit number
UnitCount is normaly 1 for analog and 16 for digitals

0x,0b,0o formatting is recognized.

For example to specify the time/date Seconds counter "S:23" in a PLC-5/40E as the status variable use


To use the Processor Status Run Mode bit (S:1/1) for PLC 5/10


To use the a bit in the Integer file (N22:75/1) for PLC 5


;Note: 1201 = (75 * 16) + 1, 0x50016 = 0x50000 (hex) + 22 (decimal)