HEIDENHAIN MANUALplus 620 Technical Manual page 1525

Counters
January 2012
The PLC has 48 counters, which you control via special markers with the
symbol C.
C0 to C47 are reserved as start markers for the timers, C48 to C95 are
reserved as process markers.
The key name of the counter is freely selectable in the machine configuration.
The process marker (e.g. C48) is defined with the optional machine parameter
MP_run. If no value is entered in MP_run, the control uses the key name of
the counter as process marker.
You must define the default values for the counters in machine parameter
MP_value. As the time unit, under MP_unit you can choose between
seconds and PLC cycles.
After you have set a marker from the C0 to C47 range, the control loads the
counter with the value that is saved in machine parameter MP_value. As the
time unit, under MP_unit you can choose between seconds and PLC cycles.
The marker range C48 to C95 (process markers) indicates whether the counter
has expired. Use markers C96 to C143 (enabling markers) to start and stop the
counter.
The optional machine parameters MP_start and MP_gate are not evaluated
by the control. The PLCdesignNT development environment uses them for the
automatic generation of PLC definition files.
Example:
Logic diagram for counter C1
Counter default in [counter] = 10 (PLC cycles)
8.4 Operands 1525