Troubleshooting and Replacement of Micro Innovation WINbloc Distributed I/O System

The combination module integrates input and output together, providing 8 or 32 channels. For example, CAN-4DI/4DO/0.5A-PK has 4 inputs and 4 outputs, while CAN-24DI/8DO/0.5A-PK has 24 inputs and 8 outputs. Combination modules are suitable for space limited situations, reducing the number of modules and wiring workload. The relay module provides 8-channel or 16 channel normally open contacts, model CAN-8 (16) DO-R-NO. Relay output is suitable for AC loads or situations that require complete isolation, but the contact life is limited. For frequent switching, transistor output or solid-state relays should be selected.

Analog I/O module

The analog input module has 4 channels, with input ranges including ± 10 V, 0...+10 V, 0/4... 20 mA, a resolution of 16 bits, reverse polarity protection, and model CAN-4AI/UI. This module is suitable for continuous signals such as pressure, flow, displacement, and valve feedback. When wiring analog signals, shielded cables must be used, with the shielding layer grounded at one end to avoid parallel wiring with power cables. If the signal source is a two-wire transmitter, it is necessary to confirm whether the module provides loop power supply; If it is a four wire system, it will be powered separately.

The PT100 input module CAN-4AI/PT100 has a resolution of 0.1 K or 0.1 W, suitable for temperature measurement. The three wire PT100 can compensate for line resistance, while the two wire system is simple but has lower accuracy. The CAN-4AI/Thermo thermocouple input module supports K, J, R, S, T, N, E, and B type thermocouples with a resolution of 1K. If the thermocouple signal is weak, compensation wires must be used and cold end compensation should be noted. There is usually a cold end sensor inside the module. If the ambient temperature changes greatly, it is recommended to compensate for the external cold end.

The analog output module CAN-4AO/UI has 4 channels, outputs ± 10 V or 0/4... 20 mA, 16 bit resolution, and reverse polarity protection. Output is used to control proportional valves, frequency converters, positioners, etc. The combination module CAN-3AI/IAO/UI provides 3-channel input and 1-channel output, suitable for small closed-loop control. The accuracy of analog modules is greatly affected by power supply, grounding, and shielding. It is recommended to use a multimeter to measure the output during debugging and perform range calibration on the PLC side.

Wiring and base module

The wiring of WINbloc is completed through the base module. The base module is available in 2-wire, 3-wire and 4-wire connection versions to accommodate different sensors and actuators. The tension clamp terminal is a major feature of WINbloc, which can insert wires without tools, has reliable contact, and is resistant to vibration. When wiring, strip the wire to a length of about 8 to 10 mm, insert it and gently pull to confirm locking. Each base module corresponds to an electronic module, which is pluggable and easy to replace without affecting wiring.

Modular design allows the entire I/O line to be mixed and matched. Digital, analog, and relay modules can be arranged arbitrarily, but attention should be paid to the power supply and bus capacity. The maximum limit of 10 I/O modules is to ensure stable internal bus power supply and communication. If there are more than 10 modules, it is necessary to add bridge modules or use repeaters. There is a mechanical interlock between the base modules, which should be clamped onto the DIN rail before inserting the electronic module during installation. When disassembling, first unplug the electronic module, and then remove the base.

Shielding and grounding are key components of analog systems. The shielding layer of the analog signal cable should be connected to the shielding terminal of the base module or the PE row inside the cabinet. If the on-site interference is severe, a double shielded cable can be used, with the outer shield grounded at both ends and the inner shield grounded at one end. Although digital signals have strong anti-interference capabilities, it is still recommended to use shielded cables for long-distance transmission, especially for high-frequency pulse signals.

Debugging and Address Setting

When debugging the WINBloc system, first confirm that the bridge module matches the PLC master station protocol. Profibus DP requires importing GSD files on the PLC side, while CANopen requires importing EDS files. Then set the address of each I/O module. The address is set by rotating the encoding switch, usually with two knobs, ten digit and one digit. For example, for address 12, the ten bits are rotated to 1 and the one bits are rotated to 2. After setting, the module must be powered off and then on again for it to take effect. If there is an address conflict, the bus cannot start and the bridging module will report an error.

Check the LED after powering on. Bridge modules typically have power LED, bus LED, and error LED. The flashing bus LED indicates normal communication, while being constantly on or off indicates a fault. The I/O module has power LED and channel LED, and the output module also has short circuit monitoring LED. If the bus LED does not light up, check the power supply, address, terminal resistance, and cables. If a module is not communicating, check the module address and internal bus connection. If the output short-circuit LED lights up, disconnect the loads one by one and find the short-circuit point.