Analog Input Module | IMASI23 | ABB

Technical Specifications

The IMASI23 Analog Input Module is a Harmony rack I/Omodule that is part of the Symphony Enterprise Managementand Control System. It has 16 analog input channels thatinterface isolated thermocouple, millivolt, RTD, and high levelanalog signals to a controller with an analog-to-digital conversion resolution of 24 bits. Each channel has its own analog-to-digital converter and can be independently configured tohandle the desired input type. 

These analog inputs are used bya controller to monitor and control a process.The IMASI23 module can be used as a direct replacement forthe IMASI03 or IMASI13 modules with only minor modifications. Changes to specification S11 in function code 216 arerequired to handle the differences in resolution choices. Verification of power supply sizing calculations and system currentrequirements could be necessary because of the change inpower consumption.

Functional Operation

The ASI module is an intelligent module with an onboardmicrocontroller and memory. It interfaces to a controller overthe I/O expander bus. An onboard microcontroller allows theASI module to perform the input channel processing. Thisallows the controller to do other tasks. Input processing tasksinclude error compensation, adjustments, and conversion toengineering units.

Each channel provides underrange, overrange, and open inputdetection. Onboard circuitry detects either open field wires or adisconnected termination unit cable. Open input detection isprovided for millivolt, thermocouple, RTD, 1 to 5 VDC, and 4 to20 milliampere input types and can detect any combination ofopen input wires.

Cold Junction Reference

The ASI module measures the cold junction RTDs on the termination unit of the analog input module. This results in anaccurate reading of the ambient temperature at the field wiretermination area. This value can be used by the ASI module tocompensate for voltages generated from the bimetal connections made by terminating the field wires (thermocouplewires) onto the terminal blocks of the termination unit.

The block address of the cold junction reference used by thermocouple inputs on the ASI module is contained in FC 215,specification S3.

Each analog input module configured for a thermocouple inputrequires a cold junction reference. Each analog input modulecan only have one reference which can be used by up to 16thermocouple inputs. The exception to this is when one of theinputs is used as a remote cold junction reference.

Technical FAQ

Q: Can the IMASI23 replace older modules like the IMASI03 or IMASI13?
A: Yes, it serves as a direct replacement with minor modifications. You must update specification S11 in function code 216 to accommodate resolution differences and re-verify power supply load calculations.

Q: Does it support cold junction compensation for thermocouples?
A: Yes, the unit includes built-in cold junction reference switching for accurate thermocouple readings.

Q: How do you perform diagnostics on the module?
A: The hardware interfaces directly with local board switches and status LEDs to support active diagnostic mode operations.

Q: Do you supply brand-new, original parts or second-hand refurbished items?

A: Our stock consists of Original New items; all products undergo quality inspection to ensure they are fully functional.

Q: What guarantees are included with the shipment?
A: All items in stock are tested by engineers, packed in professional ESD packaging, and shipped via express logistics with a global delivery time of 24–48 hours.

Q: How long does global shipping take?
A: Stock items are typically dispatched within 24 hours. Shipments are sent via DHL or FedEx Express, taking approximately 3–5 days to reach Asia, 4–6 days to Europe and the Middle East, and usually arriving within a week in major industrial regions worldwide.

Q: If the model I need is not listed on the website, can I request a quote?
A: Yes. We hold over 200,000 SKUs of industrial spare parts in stock, and many long-tail models are not listed in full. You can send us an RFQ (Request for Quote) directly, and we will provide wholesale pricing promptly.

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