The Model 8505 from Calex Mfg. Co. Inc., Concord, CA, is an analog-to-frequency converter for single- or multiple-channel PLC I/O systems that converts a 4–20 mA sensor output into a PLC frequency input. The 3.78 by 1.06 by 1.65 in. module operates into the 24 V, 7 mA PLC discrete counter input and features 1–5 kHz output frequency for a 4 µA/Hz resolution, output linear to 0.01% with accuracy of better than 0.1%. The output is an isolated floating optocoupler that provides DC isolation from the input and DC power. All connections are made to screw terminals.
Analog-to-Frequency Signal Conditioner from Calex
Calex Mfg. Co. Inc.