Cabinet Watchdog And Voltage Monitor

The Cabinet Watchdog (CWD) and Voltage Monitor is used to provide cabinet voltage measurements and watchdog services. The CWD can sample up to 4 different DC analog voltages (0 to 25.6 VDC). The sample rate for each channel is 10 samples per second and is averaged to 1 sample per second. The CWD can sample up to 2 opto-isolated relay inputs (5 VDC to 24 VDC) and up to 6 TTL level inputs. The sample rate for the digital channels is 10 samples per second. The states of the digital inputs are accumulated for 1 second and the majority is used to determine the on or off state at a 1 sample per second rate. The CWD has 2 opto-isolated relay outputs for driving external mechanical relays for controlling such things as cabinet power. The output relays are open collector, and can sink up to 30 milliamps with a maximum collector voltage of 30 volts. In Polled Mode, the CWD provides a watchdog function and expects to receive at least 1 polling request per hour. If the request is not received, the opto-isolated relay outputs are activated (active low) in sequence. The first relay output (OC1) is activated for 1 second before the second relay output (OC2) is activated. The relay OC2 is active for 10 seconds while the relay OC1 is active for 12 seconds. Hence, OC1 becomes active 1 second before OC2 becomes active and becomes inactive 1 second after OC2 becomes inactive.

When used with SmarTek's Power Relay Module, the Cabinet Watch Dog can monitor cabinet communications and temporarily interrupt power to cabinet devices to reset and restore cabinet functions.  The power relay module also provides fusing of power supplies and power distribution points in addition to relay control of cabinet power.

Part of the complete cabinet integration solution.  See our Device Server to convert your direct serial or dial-up connection to an Ethernet environment.

Cabinet Watchdog User Guide