IC697ALG440 GE IC697ALG44O Analog Input Module NIB PLC

GE Fanuc IC697ALG440 | Series 90-70 16-Channel 4–20mA Current Input Expander Module — 16-Bit / 2.4ms

Extending the Series 90-70 Analogue System — 16 More Channels per Module

The IC697ALG440 is the current input expander module for the GE Fanuc Series 90-70 analogue input system. It does not operate independently — it is always paired with the IC697ALG230 base converter module. The IC697ALG230 provides the analogue-to-digital conversion hardware and the communication path to the Series 90-70 CPU. The IC697ALG440 adds 16 additional 4–20mA input channels to the base converter's initial 8 channels, extending the complete system's analogue measurement capacity in blocks of 16 channels per expander.

One base converter supports up to seven expander modules — a mix of IC697ALG440 (current) and IC697ALG441 (voltage) expanders. Fully populated, the system reaches 120 analogue input channels: 8 from the base converter plus 7×16 from the expanders. All channels across the base and all expanders are managed by the single base converter's ADC. The ADC uses an analogue multiplexer to scan each input in sequence — the 2.4ms update rate applies to all channels in the subsystem.

Each of the 16 inputs is individually configurable for differential measurement and individual user scaling per channel. No hardware jumpers or DIP switches control the channel configuration — the module reads its configuration from the Series 90-70 CPU's software configuration, downloaded at startup. Each input channel uses one word of %AI memory in the Series 90-70 at 16-bit resolution. The module must be placed in the same rack as the IC697ALG230 base converter and physically adjacent to it.

Key Specifications

Wiring Architecture — Parallel Connection Between Modules

The IC697ALG440 connects to the IC697ALG230 base converter through a simple parallel wiring scheme using four terminals. The base converter's terminals 36 and 38 serve as the analogue expansion signal connection; terminals 37 and 39 form the differential data bus for communication between the base and expanders. A shield ground connection at terminal 35 is available for shielded cable installations, though shielding is optional.

FAQ

Q1: Can the IC697ALG440 be used without the IC697ALG230 base converter?

No. The IC697ALG440 is an expander module — it has no analogue-to-digital converter of its own. The IC697ALG230 base converter provides the ADC, the communication interface to the Series 90-70 CPU, and the power control for the complete analogue subsystem. The expander is an input multiplexer extension; the base converter does the conversion. Installing an IC697ALG440 without the IC697ALG230 produces no analogue data in the PLC.

Q2: How many IC697ALG440 modules can be connected to one IC697ALG230 base converter?

Up to seven expander modules total can connect to one IC697ALG230 base converter. This gives the complete subsystem 8 base channels + 7×16 = 120 channels. The seven expanders can be any combination of IC697ALG440 (current) and IC697ALG441 (voltage) modules — they can be mixed in any proportion up to the seven-expander maximum.

Q3: Does the IC697ALG440 handle both 4-20mA and 0-20mA, or only 4-20mA?

The IC697ALG440 current expander accepts 4–20mA input signals as its standard current loop range. For configurations requiring 0–20mA or voltage inputs, different channel configurations through the base converter or different expander variants apply. Confirm the required input range from the field transmitter specifications before selecting the expander type.

Q4: How are IC697ALG440 channel faults detected?

The ALL OK LEDs on the module should all be illuminated solid green during normal operation. A blinking or off OK LED indicates a channel fault or module fault. In the PLC programme, open wire conditions on 4–20mA channels typically result in the channel reading below the 4mA live-zero threshold — the base converter's open-wire detection capability can flag these conditions through the %AI data in the CPU.

Q5: Where is the IC697ALG440 sourced after discontinuation?

Through the GE Fanuc Series 90-70 aftermarket — Emerson Automation-aligned spare parts dealers, tested surplus suppliers, and repair services. Several revision letters of the IC697ALG440 (A, B, C, D etc.) are available. All revisions serve the same function; confirm availability from the supplier.