TM3AI8

Configured for analog signal acquisition in Modicon M221, M241, M251 and M262 controller systems, the Schneider Electric TM3AI8 (TM3AI8 Analog Input Module) provides eight voltage or current input channels through removable screw terminals. It supports 12-bit or 11-bit plus sign conversion and exchanges input data with the controller through the Modicon TM3 expansion bus.

Hardware Specifications

Parameter	Specification
Model	TM3AI8
Brand	Schneider Electric
Series	Modicon TM3
Product Type	Analog input module
Compatible Controllers	Modicon M221, M241, M251, M262
Analog Inputs	8
Input Ranges	4-20 mA, 0-20 mA, 0-10 V, -10 to 10 V
Resolution	12 bits; 11 bits + sign
Sampling Duration	1 ms
Conversion Time	1 ms + 1 ms per channel + 1 controller cycle time
Input Impedance	<= 50 Ohm for current input; >= 1 MOhm for voltage input
Continuous Overload	40 mA current; 13 V voltage
Absolute Accuracy	+/- 1 % FS; +/- 0.2 % FS at 25 deg C
Repeat Accuracy	+/- 0.5 % FS
Cross Talk	<= 1 LSB
Insulation	1500 V AC input-to-supply; 500 V AC input-to-internal logic
Power Consumption	35 mA at 5 VDC no load; 40 mA at 5 VDC full load; 30 mA at 24 VDC no load; 40 mA at 24 VDC full load
Rated Supply Voltage	24 VDC
Dimensions	23.6 mm W x 70 mm D x 90 mm H
Weight	0.11 kg
Operating Temp	-10 to 55 deg C horizontal; -10 to 35 deg C vertical
Storage Temp	-25 to 70 deg C
Protection Rating	IP20
Cable Type	Twisted shielded pair, input cable length up to 30 m
Electrical Connection	Removable screw terminal blocks, 3.81 mm pitch
Mounting	TH35-15 or TH35-7.5 DIN rail per IEC 60715; plate or panel with fixing kit
Certifications	CE, UKCA, RCM, EAC, cULus, cULus HazLoc
Standard	IEC 61131-2
Country of Origin	JP
GTIN	3606480648922

Analog I/O Density and Expansion Bus

The TM3AI8 provides eight analog channels in a 23.6 mm wide module. Input data is transferred through the TM3 bus connector when the module is assembled with a compatible Modicon M2xx controller and other TM3 expansion modules. The same bus connection distributes the required expansion data and power between interconnected TM3 modules.

The input stage accepts either voltage or current signals. The specified LSB values are 2.44 mV for 0-10 V, 4.88 mV for -10 to 10 V, 4.88 uA for 0-20 mA, and 3.91 uA for 4-20 mA. Temperature drift is specified at +/- 0.01 % FS/deg C, with non-linearity of +/- 0.2 % FS.

Frequently Asked Questions

Q: What analog signal ranges can the TM3AI8 accept?
A: The module accepts 4-20 mA, 0-20 mA, 0-10 V, and -10 to 10 V analog inputs.

Q: What isolation is provided by the input circuitry?
A: The input circuit is insulated from the supply at 1500 V AC and from internal logic at 500 V AC.

Q: What cable arrangement is specified for the analog inputs?
A: Schneider Electric specifies twisted shielded pair cable for the inputs, with an input cable length up to 30 m.

Field Installation Guidelines

• Install the module on a TH35-15 or TH35-7.5 DIN rail conforming to IEC 60715, or on a plate or panel using the specified fixing kit.
• Engage the TM3 interlocking mechanism and expansion bus connector correctly before energizing the controller assembly.
• Use the removable screw terminals for analog signal and supply wiring.
• Route analog input wiring separately from high-current, switching, and high-frequency power conductors where practical.
• Use twisted shielded pairs for analog signals and terminate the shield according to the plant grounding and EMC design.
• Observe the specified input ranges and avoid exceeding the 40 mA current or 13 V voltage continuous overload limits.
• Maintain the specified installation temperature limits: -10 to 55 deg C for horizontal installation and -10 to 35 deg C for vertical installation.
• Keep the IP20 module inside an enclosure providing the required environmental and touch protection.
• Verify polarity, channel assignment, terminal tightness, and the controller configuration before applying operating power.

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