IC670MDL740 IC67OMDL74O GE Fanuc IC670MDL740 POSITIVE OUTPUT MODULE

GE Fanuc IC670MDL740 | Field Control 16-Point Positive Logic DC Output Module — 12/24V DC / 0.5A / 4A Total / BIU Mount / Discontinued

Positive Logic Outputs — Sourcing 16 Field Devices from One Module

The IC670MDL740 provides 16 sourcing (positive logic) DC outputs for the GE Fanuc Field Control distributed I/O platform. Sourcing outputs supply current to the load — the output transistor switches the positive supply to the load terminal, and the load returns to the negative (common) supply. This is the positive logic convention, and it is the correct interface for NPN-sensed field devices and standard 24V DC coil loads in most industrial applications.

All 16 outputs form a single group sharing one external power supply connection, protected by an internal 5A fuse. The module monitors the external supply voltage — if it drops below 9.8V DC, the Bus Interface Unit (BIU) registers a fault condition, alerting the control system to the supply failure before complete output loss.

Each output point has a dedicated LED indicator — one of the most practical features for installation and troubleshooting. With 16 illuminated LEDs, the module's complete output state is visible from the front face without connecting diagnostic equipment. A relay coil that should be energised but whose LED is off immediately identifies a programme, wiring, or fuse issue as the fault point.

Key Specifications

Field Control Platform — BIU-Mounted Architecture

The IC670MDL740 installs on a GE Fanuc Field Control Bus Interface Unit (BIU). The BIU provides the communication bus connection to the host controller (GE Series 90-30, Genius Bus, or similar), the backplane power supply for the module's logic, and the physical mounting structure. The IC670MDL740 requires a separate external 24V DC power supply for the output switching circuits — this external supply connects through the 5A internal fuse.

The 4A module-level current limit is the binding constraint: if five or more outputs simultaneously drive loads at 0.5A each (totalling over 4A), the remaining outputs in that activation cycle must draw less to stay within the module rating.

FAQ

Q1: What is "positive logic" and how does it affect field device wiring?

Positive logic (sourcing) means the output supplies current from the positive supply rail to the load. The load returns to the negative (common) supply. This is correct for NPN load devices where the load switches on when current flows from positive through it to common. The opposite convention — negative logic (sinking) — switches the negative side. Confirm the field device's connection polarity matches the IC670MDL740's sourcing output type before wiring.

Q2: All 16 outputs are in one group. What does this mean for wiring?

All 16 outputs share a single external power connection and the 5A fuse. There is no group-level isolation between output points — they all operate from the same external supply. This simplifies wiring (one positive feed and one common for all 16 outputs) but means all 16 must be powered from the same field supply. Loads at different voltages cannot be mixed in the same module.

Q3: The fuse LED is lit. How is this fault resolved?

The 5A internal fuse for the external power supply has blown. Identify and remove the overload or short-circuit condition in the field wiring before replacing the fuse — reconnecting power to a faulted circuit blows the replacement immediately. After resolving the overload, the module fuse requires service replacement by a qualified technician; fuses cannot be replaced by the user in most IC670 module designs. Contact GE Fanuc service support.

Q4: Can the IC670MDL740 be substituted with another GE Field Control output module?

Within the GE Fanuc Field Control series, adjacent module variants differ in output logic type, voltage class, current rating, or group structure. Confirm the replacement module carries the identical output type (positive logic, 16-point, 12/24VDC, single group) as the IC670MDL740 before substituting. A module with different output logic or group count changes the field wiring requirements.

Q5: Where is the IC670MDL740 sourced after discontinuation?

Through the GE Fanuc Field Control aftermarket — GE automation parts dealers, tested surplus suppliers, and industrial control system component specialists. Request confirmed functional testing on any used IC670MDL740. Confirm the IC670MDL740 part number (or suffix J/K revisions if applicable) matches the installed module from the label on the existing unit.