Counter Operation; Timer Operation - Satec System 295 Installation And Operation Manual

4.12 Counter Operation

The PM295 provides 8 multi-function counters that can be used for different
purposes. The counter readings are represented by a non-negative number in the
range of 0 to 999,999,999. After the maximum value, the counter will rollover to
zero. The present counter readings can be monitored through the front panel and
communications, and used as triggers for setpoint operation. All counters can be
individually written or reset all together via communications.
The primary usage of the counters is the counting of incoming pulses. Each counter
can be connected to one of the eight discrete inputs that should be configured as
pulse input. Pulses are counted in the direct order only. The maximum rate of pulses
the counter can follow is 10 Hz.
Each counter can be independently acted via a setpoint to count varying events, for
instance, to count the number of setpoint operations. The actions available are
incrementing, decrementing the counter, and resetting the separate counter, or all
counters together. Counting events can be made in either direct (up to the maximum
value allowed) or reverse (up to zero) order.
Each counter input can be independently scaled (weighted) by specifying a scale
factor in the range of 1 to 9999 units per pulse. This means that each counted pulse
or setpoint action on the counter will add to or subtract from it the specified number
of units.

4.13 Timer Operation

Four interval timers with a one-second resolution are provided by the PM295 for
repeated setpoint operations. The counting interval range for those is 1 to 9999
seconds. The timer accuracy is about ±0.1 sec. The first time, the timer runs
immediately after the user specified a non-zero timer interval, and stops with
announcing the dedicated timer event when the interval expires. The next time, the
timer runs by a setpoint operation. Thus, the timer synchronization base might be
affected if the setpoint operation or release is delayed.
Each timer can be connected to a single setpoint in one of two ways: as a solitary
condition for the setpoint operation, or in conjunction with other conditions using an
AND operation. In the first mode, the setpoint will be operated continuously at
specified intervals. In the second mode, called gated mode, the setpoint operations
will depend on the additional conditions, which can be any triggers allowed, except
of events having pulse nature.
Operation Techniques 75