Honeywell | 621-9939 | Serial Link Module SLM Remote I/O

Product Overview

The Honeywell 621-9939 is a Serial Link Module (SLM) that manages serial I/O data transfer to and from remote I/O. It contains its own processor and data table, operating asynchronously to the main processor, and supports up to two serial channels.

Technical Specs

• Type: Serial Link Module (SLM)
• Channels: 2 serial I/O channels per module
• Function: Controls data transfer between processor and remote serial I/O
• Operation: Asynchronous to main processor
• Termination: Requires terminating resistors at channel ends
• System: Honeywell IPC / 620-9000 series
• Typical current: Approx. 2 A at 5 V DC

Key Features

• Independent processor for serial communication
• Supports dual serial channels
• Enables distributed remote I/O architectures
• CRC and timeout error checking

FAQ

• Channels? Two serial I/O channels.
• Function? Serial link to remote I/O.
• System? Honeywell IPC 620/9000 family.

Installation Guide

1. Install the SLM in the designated processor chassis slot (L or M).
2. Connect serial cables and install terminating resistors at both ends of each channel.
3. Configure channel parameters and addresses.
4. Power up and verify communication status.
5. Test data transfer with remote I/O drops.

Selection Tips

• Required for systems using serial remote I/O.
• Confirm cable type and termination values.
• Critical spare for distributed IPC architectures.