4222 I/F Converter

Universal Input to frequency converter

  • Universal I/f Converter
  • Input for RTD, TC, Ohm, potentiometer, mA and V
  • Frequency output NPN, PNP and TTL
  • Generates frequencies from 0.001…25000 Hz
  • 2-wire supply > 16 V
  • Accepts 90% Standard industrial Signals
  • Universal AC or DC supply



Advanced features

  • Programmable via detachable display front (4501), process calibration, signal simulation, password protection, error diagnostics and selection of help text in several languages.


  • Linearized, electronic temperature measurement with RTD or TC sensor.
  • Conversion of linear resistance variation to a frequency signal, e.g. from solenoids and butterfly valves or linear movements with attached potentiometer.
  • Power supply and signal isolator for 2-wire transmitters.
  • Process control by way of a frequency signal transmitted to e.g. a PLC or a process computer.
  • Galvanic separation and conversion of analog signals to frequency signals.

Technical characteristics

  • When 4222 is used in combination with the 4501 display / programming front, all operational parameters can be modified to suit any application. As the 4222 is designed with electronic hardware switches, it is not necessary to open the device for setting of DIP switches.
  • A green front LED indicates normal operation.
  • Continuous check of vital stored data for safety reasons.
  • 3-port 2.3 kVAC galvanic isolation.

Environmental Conditions

Operating temperature -20°C to +60°C
Calibration temperature 20…28°C
Relative humidity < 95% RH (non-cond.)
Protection degree IP20

Mechanical specifications

Dimensions (HxWxD) 109 x 23.5 x 104 mm
Dimensions (HxWxD) w/ 4501 / 4511 109 x 23.5 x 116 / 131 mm
Weight approx. 155 g
Weight incl. 4501 / 4511 (approx.) 170 g / 255 g
Wire size 1 x 2.5 mm2 stranded wire
Screw terminal torque 0.5 Nm

Common specifications


Supply voltage, universal 21.6…253 VAC, 50…60 Hz or 19.2…300 VDC
Max. required power ≤ 2.5 W

Isolation voltage

Isolation voltage, test / working 2.3 kVAC / 250 VAC

Response time

Temperature input, programmable (0…90%, 100…10%) 1…60 s
mA / V input (programmable) 0.4…60 s

Auxiliary supplies

2-w. supply (term. 44…43) 25…16 VDC / 0…20 mA
Fuse 400 mA SB / 250 VAC
Programming Communication enabler 4511 / Programming front 4501
Signal / noise ratio Min. 60 dB (0…100 kHz)
Accuracy Better than 0.1% of selected range
EMC immunity influence < ±0.5% of span
Extended EMC immunity: NAMUR NE 21, A criterion, burst < ±1% of span

Input specifications

RTD input

RTD type Pt100, Ni100, lin. R
Cable resistance per wire (max.) 50 Ω
Sensor current Nom. 0.2 mA
Sensor error detection Yes
Short circuit detection < 15 Ω

TC input

Thermocouple type B, E, J, K, L, N, R, S, T, U, W3, W5, LR
CJC via internally mounted sensor < ±1.0°C
Sensor error detection Yes
Sensor error current: When detecting / else Nom. 2 μA / 0 μA

Current input

Measurement range 0…20 mA
Programmable measurement ranges 0…20 and 4…20 mA
Input resistance Nom. 20 Ω + PTC 50 Ω

Voltage input

Measurement range 0…12 VDC
Programmable measurement ranges 0/0.2…1, 0/0.5…2.5, 0/1…5, 0/2…10 VDC
Input resistance Nom. 10 MΩ

Output specifications

Frequency output range 0…25000 Hz
Min. frequency (span) 0.001 Hz
Other output types PNP, NPN and TTL
Sensor error indication, programmable 0…26250 Hz
*of span = of the currently selected measurement range

Observed authority requirements

EMC 2014/30/EU
LVD 2014/35/EU


UL UL 508
EAC TR-CU 020/2011