GE FANUC Mixed 24VDC POS LOG input group 16 point / isolated 2 amp relay output IC200MDD845 IC2OOMDD845 IC-200MDD845

GE Fanuc IC200MDD845 | VersaMax Discrete Mixed I/O Module — 16 × 24V DC Inputs / 8 × Isolated 2A Relay Outputs / 24 Points

One Module, Two Functions — Inputs and Relay Outputs Together

The IC200MDD845 combines digital input and relay output functions in a single VersaMax I/O slot. In systems where both inputs and outputs are needed but the I/O count at a station is moderate, a mixed module reduces the number of slots occupied and simplifies the module inventory compared to using separate dedicated input and output modules.

The 16 inputs are 24V DC positive logic — the standard 24V DC control voltage for industrial sensors, limit switches, proximity detectors, and pushbuttons. Two groups of 8 inputs each read field signals and pass them to the PLC over the backplane. Positive logic (sourcing) means the sensor or switch supplies 24V DC to the input terminal to signal an ON state.

The 8 relay outputs provide a distinct advantage over transistor output modules for mixed AC/DC load switching. Each of the 8 relay outputs is individually isolated from every other relay output and from the input section — each relay is a Form A (normally open) dry contact. This means different loads at different voltages can be switched from different outputs on the same module without electrical connection between them. The relay can switch both AC and DC loads up to 2.0A, covering 120V AC, 240V AC, 24V DC, 120V DC, and everything in between within the 5–265V AC / 5–125V DC rating.

Key Specifications

Individually Isolated Relay Outputs — Why It Matters

On modules with grouped relay outputs, multiple outputs share a common terminal. If different voltages or different circuits need to be switched, common terminals force all outputs in the group to use the same voltage and polarity. The IC200MDD845's individual isolation eliminates this constraint. Each relay is a self-contained contact — the load circuit connects only to that relay's own terminals. Eight completely different loads at eight completely different voltages can all be switched from the same module.

FAQ

Q1: What carrier base does the IC200MDD845 require?

The IC200MDD845 requires a VersaMax I/O carrier (IC200CHSxxx series) for backplane mounting. The module does not mount directly to the DIN rail or panel — it snaps onto the carrier, which provides the backplane connector, the field wiring terminal block, and the mechanical mounting. Carrier selection depends on the VersaMax I/O network interface being used (Genius NIU, PROFIBUS NIU, Ethernet NIU, etc.).

Q2: What is the difference between the IC200MDD845 and IC200MDD844?

The IC200MDD844 provides 16 inputs (positive/negative logic, 24V DC) and 8 relay outputs — similar count. The IC200MDD845 is the positive logic input version, while the IC200MDD844 supports both positive and negative logic input configurations (revision-dependent). Confirm the logic configuration requirement from the installed system documentation. Both use individually isolated Form A 2.0A relay outputs.

Q3: Can the relay outputs switch both AC and DC loads on the same module?

Yes. Because the outputs are individually isolated, each relay can switch a completely different load type and voltage. One output can switch 120V AC, another 24V DC, another 240V AC — all on the same module simultaneously. The relay's dry contact simply opens and closes the circuit between its two terminals. The load circuit's voltage and current must remain within the rated range (2.0A, 5–265V AC or 5–125V DC).

Q4: What does the OK LED on the IC200MDD845 indicate?

The OK LED indicates that backplane power is continuously supplied to the module — the VersaMax backplane is energised and the module is receiving its operating power. A dark OK LED indicates the module is not receiving backplane power, which points to the power supply module, the carrier, or the backplane as the fault location rather than the IC200MDD845 module itself.

Q5: Where is the IC200MDD845 sourced?

Through the GE Fanuc / Emerson VersaMax I/O aftermarket — Emerson-authorised distributors, industrial automation parts dealers, and tested surplus suppliers. Multiple revisions exist (A through N); all serve the same function. Confirm revision compatibility with the installed VersaMax system configuration if required. GE Fanuc VersaMax products are now managed by Emerson Automation Solutions.