Digital Inputs
The digital inputs (6 total) can be dry contact or voltage (30 Volts max). Be sure to
connect the ground bus from the module to either the ground of the voltage device or
the dry contact.
The frequency of the digital inputs is calculated over a 2-second time period for the
Instantaneous Frequency and calculated over a 60-second window for the Average Frequency. For
example the Average Frequency register will be updated every 60-seconds and will contain the
average frequency of the previous 60-second period.
Digital Input Debounce
In cases where it is desired to accurately totalize digital input counts it may necessary to enable the
“digital input debounce” timer. The debounce timer is useful when dealing with dry contacts that may
otherwise produce extra counts when they close. To enable the digital debounce select “Digital Input
Debounce” from the settings pull-down menu. A typical value for a dry contact would be 100mS. Any
extra counts due to contact bounce within the debounce time setting will be ignored.
Digital (Relay) Outputs
There are four relay outputs. Two of the relays are SPDT and two are DPDT relays. The relays are rated
for the following:
30 VDC @ 2 Amps
250 VAC @ 0.25 Amps
Relay Failsafe Timers
The MIOM supports a configurable failsafe timer which is used to de-energize selected relays in event
of a communication failure.
Relay Message Failsafe Timer –This timer is reset anytime a coil write for any Modbus relay coil write
is received. Each relay can be individually enabled for failsafe operation.
If any timer expires all relays selected for “Failsafe Enable” will be de-energized.
When any relay is de-energized from a failsafe timer it will only be energized when a valid coil write is
received or the relay is commanded on from the Toolkit.
