Rockwell Automation 1760-xxxx Pico GFX-70 Controllers User Manual - Manual (Page 189)

Publication 1760-UM002B-EN-P - March 2005
Wiring with Pico GFX-70 4-79
• The first measurements are made after the CF..EN enable signal has
been activated. The value is output after the gate time has timed out.
• The contacts are set in accordance with the measured frequency.
• If the CF..EN enable signal is removed, the output value is set to zero.
High-Speed Counters
Pico GFX-70 provides four high-speed up/down counters CH01 to CH04 for
use. The high-speed frequency counters are hard wired to the digital inputs I1
to I4. These counter relays allow you to count events independently of the
cycle time. You can enter upper and lower threshold values as comparison
values. The contacts will switch according to the actual value. To specify a start
value, for example, counting from the value 1989, this can be implemented
using a CH .. counter.
The CH.. counters operate independently of the cycle time.
Counter Frequency and Pulse Shape
The maximum counter frequency is 3 kHz.
The signals must be square waves. The mark-to-space ratio is 1:1.
Wiring of a Counter
The following assignment of the digital inputs apply.
• I1 counter input for the counter CH01
• I2 counter input for the counter CH02
• I3 counter input for the counter CH03
• I4 counter input for the counter CH04
You integrate a counter into your circuit in the form of a contact and coil. The
counter relay has different coils and contacts.
IMPORTANT
To prevent unpredictable switching states, use each coil of a
relay once only in the circuit diagram. Use a counter input
for the CF, CH, CI counters only once.