621-9938R

Overview

Honeywell 621-9938R is a Serial I/O Module (SIOM) used in redundant serial I/O configurations, installed in slot N of the remote Serial I/O card file. It controls the serial I/O card file and interfaces with the 621-9939 SLM in the processor card file.

Specifications

• Model: 621-9938R

• Type: Serial I/O Module

• Application: Redundant or nonredundant serial I/O configurations

• Communication Ports: Dual ports for redundant serial I/O lines

• Terminating Resistors: 200 or 300 ohm required at each extreme end of the serial channel

• Optional Accessory: 621-9928R Serial Link Selector (SLS) for link switching to active processor

Configuration

• DIP Switch Modules: Four 8-position and one 4-position

• Functions:

  • Select module starting address (range 0–2032, increments of 8)

  • Card fault recognition

  • Communication fault responses

  • Normal or test mode operation

  • Number of I/O points per card file slot

• SW1: Absolute starting address selection

• SW2: Rack output states in case of fault, auto-test or normal operation

• SW3–SW5: Number of I/O points per card file slot

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