13-10 VersaMax Modules, Power Supplies and Carriers User's Manual
GFK-1504N
13
IC200MDD841
Mixed Module, 24 V DC Positive Logic Input 20 Points / Output 12 Point /
(4) High-speed Counter, PWM, or Pulse Train Configurable Points
Type
A Counters
The Type A counter is one 16-bit counter that can count up or down.
Configurable high and low limits set the counter’s range.
The counter can either count continuously within its limits, or count to either limit
then stop (one-shot mode). In continuous counting, the Accumulator (see
below) wraps when the count limit is reached and continues counting. For
example, if the Count Direction is up, when the count exceeds the High Limit by
1, the Accumulator value wraps to the Low Limit. In one-shot mode, the counter
stops at the limit.
In the following example, the counter has been configured to count on the low to
high transition of the Pulse input. The Count signal represents an internal signal
that indicates where counting occurs with respect to the pulse input.
Pulse Input
Count
N 2
N 1
N
Accumulator
Value
The Type A counter has an Accumulator register, a Counts-per-Timebase
register, a Strobe register, high limit, low limit, and ON/OFF Preset values.
These are 16-bit signed numbers. The values selected for the Preload,
Accumulator, On Preset, and Off Preset registers must be within the counter
limits. The maximum pulse repetition rate of the Preload signal and Strobe must
be less than 2 kHz, and the duty cycle for both must be such that the signal is
high for at least 250 microseconds.
Up or Down Counter (16-bit)
Preload Value
(16-bit)
Strobe Register
(16-bit)
Counts per
Timebase
(16-bit)
Strobe
Count
Pulse
Preload
Accumulator
(16-bit)
On/Off Presets
Output
Preload
/Strobe
