4
72-910-24 Revision H
Interlock
MicroVision
has a dry contact interlock option for input number 5 that will de-activate all of the control
output relays upon an interlock condition indication. The interlock input requires that an auxiliary
relay (not supplied) is installed across the boiler operation controls to produce a dry contact closure
when the boiler is online and an open circuit when the boiler is offline. The Alarm message “Interlock
on” will flash on the screen when the controllers interlock feature is on.
If an interlock or other alarm condition exists, the four (4) LED’s will flash until
the alarm condition is cleared
.
Water Meter
Each input may be programmed as water meter inputs that are capable of reading a dry contact
water meter. Input number one can be set to read a Hall Effect type water meter. Through
programming this input can be used to feed inhibitor as well as totalizing water consumption.
Alarm Relay (Relay #5)
MicroVision
has a dedicated dry contact relay that can be used to interface with process control
equipment or visual indicators. This relay is un-powered and may also be programmed as a timer.
4-20mA Output
Connect your 4-20mA equipment to J8 (Fig. 7) pins + and -. The 4-20mA output uses 24VDC as a
supply voltage. See the “Conductivity Menu” section (Page 24) for setting up and calibrating the 4-
20mA output. When in the timed sample, or the sample and hold modes the 4-20mA output will only
update during the sample time and the hold times. During the interval times the output will remain at
the last sample value.
