(iii) programme failure (run-time output abnormal)
Fragments, common causes, solutions
Plc is not able to download 1. Plc is running in “run”; 2. There is a grammatical error in the program; 3. The project model does not match the actual plc model 1. Dial the plc mode switch to “stop” (stopping mode); 2. Click on “grammatical check” in the software to fix red-marked errors (e. G. Error in command format, memory address crossing); 3. Select a model (e. G. Cp1h-xa40dt-d) consistent with plc when creating a new project
Timer/calculator does not act 1. Timer/meter address is reused; 2. Trigger condition is not met (e. G. Contact not enabled); 3. Set value error (e. G. Unit confusion)
The output end(y) does not respond 1. Plc is in "stop " mode; 2. Logic error of the program (e. G. No contact guide, reset of the loop); 3. Output locking setting error 1. Dial the mode switch to "run" (run mode); 2. Monitor whether the output circle is "on" (green) and screens for the prior logic; 3. Remove unnecessary output locking instructions (e. G. Keep) and simplify the logical test
(iv) connection failure (input/output no response to hf causes)
Fragments, common causes, solutions
Input signal (di) non-responsive (sensor triggers but no di light) 1. Sensor polar backlash (npn/pnp confusion); 2. Sensor power is not connected; 3. Connection endpoints are loose/exposed; 1. Identification of sensor type: npn sensor com connects dc24v negative, pnp is positive; 2. Measurement of sensor power is dc24v by 10,000 meters; 3. Replugging of endlines and screwding (avoiding false connections)
The output signal (do) is not responsive (wireline on but not actionable by the implementer) 1. Implementation power is not connected; 2. Loading power currents exceed do end-end ration values (e. G. Direct-drive high-power electric machines); 3. Output end damage 1. Checking whether the implementation power source (e. G. Dc24v or ac220v) is normal; 2. Adding intermediate relays (do-driven relays, relays controlling large power load); 3
1. Output short circuits (err lights flashing + jumper); 1. Output end and com end short circuits; 2. Executor wire short circuits; 3. Cable insulation faults 1
Iii. Crash screening process for new hands (five steps complete)
1. Viewing indicator lamps: determination of major types of malfunction through pwr (power), err (failure), run (run) lamps
2. Power measurement: the normality of plc input power, i/o modular power, sensor power
3. Checking wires: focus on end-end hardening, polarity of sensors/implementers, overloading
4. Inspection of communications: confirmation of mode of communication, drive, port/ip settings, replacement of cable tests
5. Interchange procedures: monitor the logic of the procedure, screen for grammatical errors, duplicate addresses, whether the trigger conditions are met。
Iv. Hits of news
- power outage operations: wiring and extraction modules must be out of power to avoid short-circuit burning of cpus or modules
- backup of the program: backup of the original file before changing the program and quick recovery in case of failure
- endmark: label the endpoint number (e. G. X0 = starter button, y0 = generator is turning) at the time of the connection, to facilitate searching
- replacement testing: replace tests with normal equipment (quick location of the failure source) if the module/sensor is suspected to be damaged。
