Allen Bradley 1762-OW16 Output Module

The output wiring is completed on the finger safe terminal block. When wiring, keep the finger safety cover in place, and the wire should be routed from below the pressure plate. Stripping ends or 6.35mm fork shaped terminals can be used. Each terminal can connect up to two wires at most; Solid wire uses # 14~# 22 AWG, stranded wire uses # 16~# 22 AWG, and the wire has a temperature resistance of at least 90 ° C. The recommended torque for terminal screws is 0.90 N · m (8 in lb), and it is necessary to confirm that the pressure plate is pressing the wire, rather than just tightening the screw. Prevent wire scraps from falling into the module during wire stripping; Clean up the wiring before powering on. If the finger safety cover is removed for wiring, the wire will block the cover and usually cannot be reinstalled, so try to use a cover for wiring.

The maximum continuous current at each output point is 2.5 A, the maximum current at each common terminal is 8 A, the maximum current at each module is 16 A, and the maximum total controlled load is 1440 VA. Group 1 and Group 2 need to calculate the common terminal current separately, and it cannot be assumed that there is no problem by evenly distributing the 16 points; If a group of 8 points simultaneously carry a large load, the common end may reach the upper limit of 8A first. When the total current of the module reaches 16 A, consideration should also be given to the heat dissipation inside the cabinet. The maximum heat dissipation of the module is about 5.6 W. The minimum output conduction current is 10 mA. If the load is a dry contact or a small relay, the current may not be reliably attracted due to being too small. It is necessary to parallel a dummy load or use a suitable intermediate relay instead. Turning off the leakage current to 0 mA is an advantage of relay output, but the contact life is greatly affected by the load type and surge.

Contact capability and inductive load protection

The output is a normally open relay with a voltage range of AC 5-265 V and DC 5-125 V. Contact rating varies with voltage: at 240 V AC, each point has a continuous 2.5 A connection capacity of 7.5 A, a disconnection capacity of 0.75 A, a connection capacity of 1800 VA, and a disconnection capacity of 180 VA; for DC applications, the connection/disconnection current is estimated by dividing 28 VA by the actual voltage, and the connection/disconnection does not exceed 2 A when it is below 14 V. The specific selection should be calculated based on the actual voltage, load type, and surge current, and not just the steady-state current.

When driving inductive loads such as contactor coils, solenoid valves, and brakes, it is recommended to add surge suppression at both ends of the load: RC or varistors should be used for AC coils, and freewheeling diodes should be used for DC coils, but diodes will prolong the release time. If fast release time is required, bidirectional transient suppression or varistors should be selected. When left unchecked, the high voltage at the moment of disconnection can cause arcing, accelerate contact erosion, and even lead to adhesion. The module itself does not have arc extinguishing capability, and external suppression is the key to extending the contact life.

I/O mapping and programming verification

1762-OW16 occupies the lower 16 bits of a word in the output data file, with bits 0-15 corresponding to output terminals 0-15, all of which are write only. Write O0: x.0/0 to O0: x.0/15 in the program, where x is the extension slot number. The built-in output of the controller body is not at this address; The expansion module starts from slot 1. If O0:1.0/0 is used in the program and the module is actually in slot 2, the output will not act as expected. When troubleshooting "program has output but module does not operate", first check if the slot number and module model in the controller I/O configuration match, then check if the corresponding bit in the output data file is really set, and finally use a forced or testing program to verify point by point.

The I/O diagnostic LED on the module can help determine bus communication and module status, but the specific light status should be combined with the controller manual. Do not judge module failure based solely on program monitoring; First confirm that the bus cable is securely plugged in, the bus cover is fastened, the module power supply is normal, and the slot number is correct, then check the terminals and load.

Common troubleshooting

All outputs are inactive. First, check if the bus connector is fully inserted, if the wiring is loose, if the module is recognized in the I/O configuration, and if the slot number matches the program. Check the module diagnostic light and controller status again; If the module is not recognized, check the bus sequence and power distance. The power distance level of 1762-OW16 is 6, and the expansion module should not be strung backwards without restrictions. When laying out the cabinet, the distance and quantity should be controlled according to the controller manual. The public end is not connected to the power supply, and the entire set of outputs will not operate; The common terminals of Group 1 and Group 2 should be connected to L1/L2 or+DC/- DC respectively.