Reliance electric PSC7000, Operating Instructions Manual

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10-1
10 Programming
This chapter details the requirements for the user to identify the spare parts.
10.1 System Variables
When the PG module is mounted on the PSC7000 Control Card, the following variables can
be used as common system variables:
- Counter variables that count the number of pulses entered from the pulse input terminal
- Latch variable to be captured by latch input
- Analog output variable that outputs analog voltage
Some variables internally process in the PSC7000 controller like system switch variables,
and some are internally processed.
When the PG module is mounted on the slot 1 of the PSC7000 Control Card, the common
system variable can be used for the channels 1 to 5. When the PG module is mounted on
the slot 2, the common system variable can be used for the channels 6 to 11. The two types
of PG modules are MCIM-1 and MCIM-2. There are some restrictions in setting the
CHn_MULT! and CHn_REF_SEL! of MCIM-1.
10.1.1 Counter Variable (CHn_COUNTER!
）
The signals transmitted from the pulse input circuit are entered into the counter of the
PSC7000 controller. The value of the counter turns straight into the counter variable. The
counter variable is captured by every scan of the control block. The counter can count
from 0 to 65535. Once you have reached the maximum number 65535 while incrementing
the counter number (start over from 0), the counter gets back to 0. Likewise, once you
have reached the minimum number 0 while decrementing the counter number (start over
from 65535), the counter gets back to 65535. The counter cannot be reset. In the control
block task, the counter variables are read by using the PULSE_READ block.
Since the input pulses are multiplied by 1, 2 or 4, the pulse rate must be determined
beforehand.
Fig.10-1 shows the example of the counter variable when input pulse is multiplied by 4.
Phase A
Phase B
Counter
Fig.10-1 Transition of Counter Variable