Allen-Bradley 1756-OB16DK Digital Output Module

Allen-Bradley 1756-OB16DK is a 16-channel digital output module for Rockwell Automation’s ControlLogix backplane, providing 24V DC outputs with diagnostic capabilities across two groups of eight points. Each point is electronically fused and rated for up to 2 A at 30°C (1 A @ 60°C), with a total module capacity of 8 A at 30°C (4 A @ 60°C). The device operates from 19.2 to 30V DC, with a nominal 24V supply, and draws about 140 mA from the 24V rail (250 mA at 5.1V for internal logic). Switching delays are short: Off-to-On typically 60 µs (max 1 ms), and On-to-Off typically 630 µs (max 5 ms). The backplane power for the module is 4.64 W, with a maximum power dissipation around 3.3 W at 60°C and a thermal dissipation rating of 11.25 BTU/hr. The OB16DK uses 250V isolation between outputs and the backplane, but there is no isolation between individual output groups. It features electronic, software-configurable module keying and a removable terminal block option (1756-TBCH or 1756-TBS6H) for field wiring, designed for open-style enclosures and with temperature code T4A. Commonly deployed to control 24V DC loads such as actuators and indicators within ControlLogix automation architectures.

• Outputs: 16 diagnostic (8 per group)
• Operating voltage: 19.2–30V DC (24V nominal)
• Current per point: 2 A max @ 30°C; 1 A max @ 60°C
• Current per module: 8 A @ 30°C; 4 A @ 60°C
• Output delay (Off→On): 60 µs nom / 1 ms max; (On→Off): 630 µs nom / 5 ms max
• Backplane power: 4.64 W; Power dissipation: 3.3 W @ 60°C
• Isolation: 250 V (outputs to backplane); no per-group isolation between outputs
• Fusing: Electronically fused per point
• Terminal blocks: 1756-TBCH or 1756-TBS6H
• Module keying: Electronic, software configurable