The Honeywell 621-9938R, also cataloged as the 621 serial I/O module, operates as a dedicated SIOM for redundant or non-redundant communication setups within Honeywell IPC 620 series process control systems.
Hardware Specifications
Parameter
Specification
Model
621-9938R
Brand
Honeywell
Origin
USA
Weight
Not specified
Dimensions
Standard IPC 620 chassis slot size
Operating Temp
Industrial-grade range (not specified)
Power Consumption
Defined by backplane load
Module Type
Serial Input/Output Module (SIOM)
Configuration
Redundant or non-redundant serial setups
Common Version
VR 3.2
Application
Industrial process control and automation systems
4-20 mA HART Loop Protocol
The 621-9938R module supports integration with serial communication networks that interface with 4-20 mA HART loop devices. This enables deterministic data exchange between field instruments and Honeywell controllers, while maintaining channel-to-channel isolation for stable operation in noisy industrial environments.
Frequently Asked Questions
Q: Can the 621-9938R be configured for redundant communication paths? A: Yes. It supports redundant and non-redundant serial setups depending on system requirements.
Q: Is firmware version VR 3.2 mandatory for operation? A: No. VR 3.2 is a common version, but compatibility depends on the controller and system configuration.
Q: Does the module provide isolation between serial channels? A: Yes. Channel-to-channel isolation is implemented to prevent interference and maintain signal integrity.
Field Installation Guidelines
Install the module in IPC 620 chassis slots using manufacturer-specified hardware.
Verify serial cable shielding and ground termination at the controller end only.
Route serial communication cables separately from high-voltage conductors.
Confirm redundant path configuration before commissioning to avoid communication conflicts.
Perform loopback tests to validate serial integrity after installation.
