2-Input 1-Output Analog Mixed Module for Modicon M238, 0-10 V / 4-20 mA

The TM2AMM3HT combines two analog inputs and one analog output on a single 23.5 mm module for Modicon M238, Twido and Advantys OTB controllers. Each channel is configurable in software for 0-10 V voltage or 4-20 mA current, so a pressure transmitter, level sensor or flow meter can feed the controller while the output drives a proportional valve or variable speed drive.

All three channels convert at 12-bit resolution, with an LSB of 2.5 mV on voltage and 4.8 uA on current. Input error is within 0.2 % of full scale at 25 C, output error and total error are within 1 % of full scale, and repeatability is 0.5 % of full scale. Sampling takes 10 ms per channel, with a 60 ms acquisition period per channel plus one controller cycle.

Two wiring details decide whether the module works as expected. Inputs are non-differential and the negative terminals of IN0 and IN1 are connected internally, so both inputs must share the same reference. Load impedance must stay within 2000 Ohm or higher for voltage output and 300 Ohm or lower for current output; outside these limits the output signal degrades. Shielded twisted pair cable is required for both inputs and output.

The module runs from an external 24 VDC supply (19.2-30 V) and draws 50 mA at 24 V plus 50 mA on the internal 5 V bus. I/O is isolated from the internal logic and the supply by photocoupler at 500 V, and all connections land on one removable screw terminal block.

Key features
- 2 analog inputs plus 1 analog output, 3 channels total
- 0-10 V or 4-20 mA per channel, software selectable
- 12-bit resolution, 2.5 mV / 4.8 uA per LSB
- 0.2 % FS input error, 1 % FS total error at 25 C
- 10 ms sampling, 60 ms acquisition period per channel
- Photocoupler isolation, 500 V
- Shielded twisted pair cable required
- One removable screw terminal block
- 23.5 mm wide, 35 mm DIN rail mounting

Specifications
Product type: Analog input/output module
Range: Modicon M238 logic controller
Compatibility: Twido, Advantys OTB
Input channels: 2
Output channels: 1
Input signal: 0-10 V, 4-20 mA, non-differential, high level
Output signal: 0-10 V, 4-20 mA
Input resolution: 12 bit
Output resolution: 12 bit
LSB value: 2.5 mV (voltage), 4.8 uA (current)
Input impedance: >= 1 MOhm (voltage), >= 10 Ohm (current)
Load impedance: >= 2000 Ohm (voltage), <= 300 Ohm (current)
Measurement error: 0.2 % FS at 25 C
Output error: 1 % FS
Total error: 1 % FS
Repeat accuracy: 0.5 % FS
Non-linearity: 0.2 % FS
Crosstalk: <= 2 LSB
Output ripple: <= 1 LSB
Sampling duration: 10 ms
Acquisition period: 60 ms per channel + 1 controller cycle
Conversion time: 20 ms + 1 controller cycle
Stabilisation time: 20 ms
Supply voltage: 24 VDC external (19.2-30 V)
Current consumption: 50 mA at 24 VDC external, 50 mA at 5 VDC internal
Isolation: 500 V, photocoupler
Connection: 1 removable screw terminal block
Cable type: Shielded twisted pair
Mounting: 35 mm DIN rail
Protection: IP20
Dimensions: 90 x 23.5 x 70 mm (H x W x D)
Net weight: 0.085 kg
Status: Discontinued by manufacturer (Jun 2019)