The Modicon TM2AMI4LT is a 4-channel Analog Input Expansion Module from Schneider Electric's Modicon M238 logic controller range.¹ It is designed to interface standard industrial sensors (voltage and current) with the PLC.²

While it was originally designed for the M238 series, it is also compatible with the M258 and Magelis XBTGC controllers using the TM2 expansion bus.

1. Function and Performance

The TM2AMI4LT provides high-resolution conversion of analog signals into digital data that the PLC can process.³

• Input Channels: 4 Differential inputs.

• Resolution: 12-bit (equivalent to 4,096 increments).

• Sampling Time: 10ms plus 10ms per active channel.

• Isolation: Photocoupler isolation between the inputs and the internal logic to protect the CPU from field-side electrical surges.

2. Supported Input Ranges

Each channel can be individually configured for the most common industrial signal types:

• Voltage: $0–10V$ DC.

• Current: $4–20mA$ or $0–20mA$.

3. Connectivity and Installation

• Mounting: Snaps onto a standard 35mm DIN rail.⁴ It connects to the PLC or the previous expansion module via a side-mounted integrated connector.

• Wiring: Features a removable screw terminal block.⁵ This allows for "cold-swapping" the module (replacing the hardware without having to re-wire every individual sensor).

• Power: Requires an external 24V DC power supply to power the analog-to-digital conversion circuitry.