The Yokogawa ADM55-2, also cataloged as the ADM55-2 PLC Module, operates as a dedicated hardware component for digital connection and precision machine control within process control system networks.
Suffix Breakdown & Model Matrix
Model Suffix
Core Function Architecture
Architectural Application
ADM55-2
Rack-Mounted Relay Output PLC Module
Relay I/O Module Nest Frameworks
ADM55-...
Base Variant Family
Yokogawa Industrial Process Control Systems
Hardware Specifications
Parameter
Specification
Model
ADM55-2
Brand
Yokogawa
Origin
Japan
Weight
0.14 kg (0.30 lbs)
Dimensions
130.0 mm x 25.0 mm x 110.0 mm
Operating Temp
0 deg C to 50 deg C
Power Consumption
2 A max at 5.0 V DC
Output Rating
250 V AC (1.5 A), 125 V DC (0.1 A), 24 V DC (1.5 A)
Minimum Load
5 V, 10 mA
Insulation Resistance
At least 10 MΩ at 500 V DC
Channel-to-Channel Isolation and 4-20 mA HART Loop Protocol
The ADM55-2 module incorporates robust channel-to-channel isolation architecture to eliminate ground loops and prevent electrical noise propagation between external field devices and internal control node logic. It handles withstanding voltage thresholds up to 1.5 kV between field device terminals and cases, ensuring operator safety and signal integrity under severe electrical disturbances. Furthermore, internal logic executes online maintenance behavior by holding outputs at current status output modes during control rack interventions, preventing unintended actuator switching.
Frequently Asked Questions
Q: What is the maximum switching rating for alternating current loads on the ADM55-2 module?
A: The relay outputs are rated for a maximum of 250 V AC at 1.5 A or less.
Q: How does the module behave during online maintenance operations?
A: The unit holds outputs at the current status output mode when active online maintenance procedures are engaged on the control rack.
Field Installation Guidelines
Ensure that the relay I/O module nest is completely de-energized and isolated prior to inserting or removing the ADM55-2 module. Connect all external I/O wiring securely via M4 screws to the corresponding relay I/O nest terminals, verifying proper torque to prevent loose connections. Maintain a clean operating environment within 10 to 90 %RH non-condensing humidity limits, and keep signal wiring separated from high-voltage power lines to preserve insulation resistance values.
