The Allen-Bradley 1746-HSRV, also cataloged as the 1746-HSRV Servo Control Module, operates as a dedicated hardware component for generating analog velocity commands up to +/-10 V DC within SLC 500 local I/O chassis.

Catalog Number Identification

The base part number 1746-HSRV carries no suffix variations in standard distribution. The single-slot module mounts directly onto the 1746 backplane. No additional dash-number options apply to this legacy servo interface card.

Electrical & Physical Data

Backplane Bus Communication & Firmware Compatibility

The 1746-HSRV interfaces with the SLC 500 processor over the 1746 series parallel backplane using a proprietary data exchange protocol. Communication velocity depends on the installed processor model and chassis scan time configuration. Firmware flash compatibility is fixed at the hardware revision level; no field-upgradable firmware exists for this module. I/O density scaling is constrained by the 3-input / 1-output channel count per single slot. The module must reside as close to the processor slot as physical chassis layout permits to minimize backplane signal propagation delay.

Ordering Information

• 1 x 1746-HSRV Servo Control Module
• 1 x Installation instruction sheet

Mounting & Wiring Guidelines

• Chassis Placement: Install the module in the slot immediately adjacent to the processor module to reduce backplane latency.
• Grounding: Bond the SLC 500 enclosure to system earth ground using a copper conductor of adequate gauge before applying power.
• Signal Separation: Route analog velocity command wiring separately from 24 VDC discrete I/O conductors to prevent inductive coupling.
• Torque: Secure all terminal connections to the torque values specified in the SLC 500 wiring documentation.

Frequently Asked Questions

Does the 1746-HSRV support hot-swap removal under load?

No. Remove power from the SLC 500 chassis before extracting or inserting the module. Live backplane engagement can damage the edge connector contacts and corrupt processor memory.

What is the backplane current consumption of this module?

Exact backplane current draw varies by processor and chassis configuration. Consult the SLC 500 system power supply sizing manual to calculate total load against available 5 VDC and 24 VDC backplane budgets.

Can the analog output drive a load directly?

The +/-10 V DC velocity command output is a low-current signal source intended for interfacing with Rockwell Automation servo drives. Do not connect resistive loads below the drive input impedance specification.

Is the 1746-HSRV compatible with 1747-L30 or L40 processors?

Compatibility depends on the specific SLC 500 processor firmware and local I/O scan table configuration. Verify the processor reference manual for supported intelligent module types before deployment.

What wire gauge is permitted for the 24 VDC terminals?

Use solid or stranded copper wire sized between 14 AWG and 22 AWG. Strip insulation to the length indicated on the terminal block housing and tighten to prevent intermittent contact.

How are the three 24 VDC inputs wired?

The inputs accept sourcing or sinking 24 VDC discrete signals. Reference the module wiring diagram for common terminal assignments and jumper configurations based on field device type.

Can this module operate in a redundant SLC 500 configuration?

The SLC 500 platform does not natively support redundant I/O module hot standby at the local chassis level. Redundancy requires a ControlLogix architecture with 1756-series hardware.

What happens if the analog output exceeds +/-10 V DC limits?

The module clamps the output at programmed limit values. Exceeding electrical specifications due to external fault conditions may trigger a module fault bit in the processor status file.