:: Products

MU-441, MU-442, MU-446, MU-447

The MU-44x modules are designed for monitoring the state of digital signals (switches, etc.) and pulse counting. Additionally, the MU-446 and MU-447 offer a powerful computing unit for calculation immediate and total consumption (electricity meters, water flowmeters, etc.).

Digital inputs are designed for signals with 24V levels and are equipped with digital low-pass filters to suppress "ringing" on input signals. The inputs are isolated not only from other circuits (power supply and RS-485 interface), but from each other as well.

Modules MU-441 and MU-442 include four 32-bit counters with value preset and start/stop capability by Modbus RTU command via RS-485.

Modules MU-446 and MU-447 include four 109 counters with value preset and start/stop capability by Modbus RTU command via RS-485. Additionally, they are also equipped with a powerful computing unit and set of counters/timers for calculating following values:

In case of a power-off, the counter and computing unit values are backed up in EEPROM (does not require a backup battery limiting temperature range). After power-on the counters and computing unit registers can optionally continue from either a backed up value or a zero value.

Additionally, the MU-442 and MU-447 modules are equipped with real-time clock circuit (abbreviation RTC) allowing e.g. to back up the power supply failure time. RTC circuit requires a battery and these types can not be supplied for extended temperature range.

Note: In applications where more then four counters are needed, modules MU-84x or MU-32xxA series can be recommended.


Type MU-441 MU-442 MU-446 MU-447
Number of digital inputs 4
Type of digital inputs isolated, bipolar 24V
Digital input signal
(level L)
<3VDC (both polarities)
Digital input signal
(level H)
10÷30VDC (both polarities)
Overvoltage protection ±40VDC (max. 1s)
Digital input impedance 6kΩ approx.
Digital input isolation 500VDC (DIN block against other circuits)
100VDC (between DIN channels)
Number of counters 4
Counter frequency 1kHz max.
(asymmetry 40/60% max.)
400Hz max.
(asymmetry 40/60% max.)
Counter range 0÷4294967295 (i.e. 232) 0÷999999999 (i.e. 109)
Computing unit - - - - - - yes yes
Counter & computing
unit values backup
yes (EEPROM, battery-less)
Real-time clock (RTC) - - - yes - - - yes
Supply voltage 10÷30VDC
Power consumption 1.2W max.
Housing & Dimensions Modulbox 3M
Signal terminals screw terminals, wire 2.5mm2 max.