MU-841, MU-842, MU-846, MU-847
The MU-84x modules are designed for monitoring the state of digital signals (switches, etc.) and pulse counting. Additionally, the MU-846 and MU-847 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 whole digital input group is isolated from other circuits of module (power supply and RS-485 interface), but inputs are not isolated from each other.
Modules MU-841 and MU-842 include four 32-bit counters with value preset and start/stop capability by Modbus RTU command via RS-485.
Modules MU-846 and MU-847 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:
- immediate consumption; it is proportional to the signal frequency (can be configured using several parameters)
- total consumption; it is proportional to the counter value
- capturing counter and computing unit values by an external signal (e.g. quarter-hour maximum)
- capturing counter and computing unit values at a preset time (MU-842 and MU-847 modules only)
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-842 and MU-847 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 eight counters are needed, modules MU-32xxA series can be recommended.
Specifications
| Type | MU-841 | MU-842 | MU-846 | MU-847 |
|---|---|---|---|---|
| Number of digital inputs | 8 | |||
| 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) (no isolation between DIN channels) |
|||
| Number of counters | 8 | |||
| 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. | |||
