621-9938 Honeywell Parallel I/O Module 16-Channel Digital Output, 24 VDC, 0.5 A

The 621-9938 is a Honeywell Parallel Digital Output Module providing 16 solid-state outputs (24 VDC, 0.5 A per channel) for the Honeywell IPC/ISSC 600 I/O rack.

• Opto-isolated outputs - 2 kV channel-to-bus
• Short-circuit & overload protected - auto-restart after fault
• LED status per channel - instant field-device verification
• Hot-swap - replace module without shutting down rack
• Parallel back-plane - deterministic update < 1 ms

Ideal for solenoids, contactors, alarms, motor starters in power-gen, chemical, oil & gas and packaging applications.

• 16 high-side outputs - drive solenoids, contactors, lamps directly
• Short-circuit protected - auto-recovery, no fuse change
• Parallel back-plane - deterministic < 1 ms update
• Hot-swap - reduce downtime
• LED diagnostics - see blown lamps or open wires instantly
• Wide voltage range - works with 24 VDC industry standard
• Class I Div 2 - safe for hazardous petrochem areas

• Power-generation breaker control
• Chemical plant valve solenoids
• Oil & gas well-head shutdown systems
• Packaging line actuators & indicators
• Water treatment chlorine dosing pumps

• Rack: ISSC 600, IPC 600 (4, 7, 10 slots)
• CPU: any 621-6575 or 621-9935 rack controller
• Power: 24 VDC supply, 10 A fuse (external)

• 621-9938 module
• Removable terminal block (screw-type)
• Rack locking lever & label
• Calibration / conformance certificate
• Quick-install guide