LED Indicators
A fault should be immediately serviced. A fault indicator is illuminated when a problem exists. When the PLC has an active fault, find the appropriate procedure in the troubleshooting section.
The Processor's Fault Indicators
The SLC 5/04 diagnostic indicators are located on the front of the following components: Power Supply, CPU and I/O Modules.
The diagnostic indicators help trace the source of the fault. Faults can be found in the following components: Input devices, Output devices, Wiring and The controller.
A fault should be immediately serviced. A fault indicator is illuminated when a problem exists. When the PLC has an active fault, find the appropriate procedure in the troubleshooting section.
Six LED indicators are on the front of the CPU module. The indicators show the operating status of your processor. The indicators have the labels that are in the following list:"RUN", "FLT", "BATT", "FORCE", "DH+" and "RS232"
The "RUN" LED Indicator
When the green LED is illuminated, the processor is in the run mode. When the LED is flashing the processor is transferring a program from the RAM to the memory module. When the LED is extinguished the processor is not in the "RUN" mode.
The "FLT" LED Indicator
When the red "FLT" LED is illuminated, there is a fatal error. The CPU has stopped running. When the red "FLT" LED is flashing during powerup, the processor has not been configured correctly. When the red "FLT" LED is flashing the processor detects a major fault. The fault is in the processor expansion chassis or the fault is in the memory.
The "BATT" LED Indicator
When the red "BATT "LED is illuminated, the battery voltage has fallen below a threshold level or the battery jumper is not connected. When the red LED is off, the battery is functional or the battery jumper is present.
The "FORCE" LED Indicator
When the amber "FORCE" LED is flashing or the amber "FORCE" LED is on, the system's performance cannot be guaranteed. The PLC program has been modified improperly.
The "DH+" LED Indicator
The green "DH+" LED is on when at least 1 "DH+" device is attached.
The green "DH+" LED is flashing. There are no active nodes on the network.
The red "DH+" LED is flashing. There are duplicate active nodes on the link with the same address.
"RS232" LED Indicator
The green "RS232" LED is flashing. This indicates that the PLC is communicating with the PC.
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| Illustration 1 | g00562938 |
The SLC 5/04 Processor
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| Illustration 2 | g00563311 |
The Processor's LED indicators are off. Refer to Troubleshooting, "System Power".
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| Illustration 3 | g00563312 |
The Processor's "RUN" LED indicator is off. Turn the keyswitch to the RUN position.
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| Illustration 4 | g00563333 |
The "Power" LED indicator is on. Refer to Troubleshooting, "Central Processing Unit Fault".
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| Illustration 5 | g00563338 |
If the "POWER" LED and the "RUN" LED is ON, the system is in normal operation. If illustration 5 is shown, and an error still exists, Refer to Troubleshooting, "System Inoperable".
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| Illustration 6 | g00563342 |
If the "POWER" LED and "FLT" LED is ON, Refer to Troubleshooting, "Central Processing Communication Error".
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| Illustration 7 | g00593498 |
If the "POWER" LED is ON and the "FLT" LED is flashing Refer to Troubleshooting, "Central Processing Unit Major Fault".
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| Illustration 8 | g00563349 |
The "POWER" LED, the "RUN" LED, and the "FORCE" LED are on. Contact the factory. This problem is beyond the scope of this manual.
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| Illustration 9 | g00563352 |
If the "POWER" LED and the "RUN" LED is on and the "FORCE" LED is flashing contact the factory. This problem is beyond the scope of this manual.
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| Illustration 10 | g00563374 |
The "POWER" LED and the "BATT" LED are ON. The "FLT" LED is flashing. Refer to Troubleshooting, "Low Battery Power".
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| Illustration 11 | g00563377 |
The "POWER" LED is ON. The "DH+" LED is flashing. The "FLT"LED is flashing or the "FLT"LED is extinguished. Refer to Troubleshooting, "Processor Cannot Find Active Nodes".
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| Illustration 12 | g00563380 |
The "POWER" LED is on. The "FLT"LED is flashing or the "FLT"LED is extinguished. The "RS232" LED is off. Refer to Troubleshooting, "Central Processing Unit Fatal Error".
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| Illustration 13 | g00563384 |
The "POWER" LED is on and the "FLT" LED is on. Refer to Troubleshooting, "Central Processing Unit Communications Error".
Thermocouple Module
The thermocouple module contains diagnostic features that can identify sources of problems. The problems may occur during power up. The problems may occur during normal operation. Each channel can receive a signal from the sensors or from the analog input devices.
Diagnostics
When you power up, a self-check is performed. The self-check is conducted of the thermocouple module. The self-check is of internal circuits, of memory, and of basic functions. During the check, the "Module Status" LED indicators are off.
If no faults are found during the power up diagnostics, the "Module Status" LED is illuminated.
When a channel bit is enabled, a diagnostic check is performed. The check verifies that the channel has been properly configured. In addition, the channel is tested for out-of-range and open circuit faults on every scan.
A failure of any channel diagnostic test causes the LED for the channel that has a fault to blink. All channel faults are indicated in bits 12 to 15.
The power up checks are complete. The thermocouple module waits for valid channel configuration data from your SLC ladder logic program. The "Channel Status" LED indicators are extinguished.
When a channel is read by the module, that data is tested by the module for a fault. If such a condition is detected the "Channel Status" LED flashes.
The Thermocouple Module LED
The thermocouple module has five LED indicators. Four of the LED indicators are "Channel Status" indicators. The "Channel Status" indicators are numbered according to the channel. One of the LED indicators is a "Module Status" indicator.
Diagnostics are displayed on the "Module Status" LED indicator. Operating errors are displayed on the "Module Status" LED indicator. Problems may be detected during powerup or problems may be detected during operation. When an error occurs the module will not communicate with the processor. The channel is disabled and the data is cleared.
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| Illustration 14 | g00562940 |
"Channel Status" LED
The channel status LED indicators are used in order to indicate information of errors and channel status. This information is contained in the channel status word. You can recover from the channel errors. After corrective action, normal operation resumes.
The Thermocouple "Module Status" LED
The module status LED indicators are used in order to indicate operating errors or module errors. You can not recover from the module errors.
LED Indicators for the Thermocouple Module
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| Illustration 15 | g00563388 |
If the "Module Status" LED is on and the "Channel Status" LED is blinking, Refer to Troubleshooting, "Thermocouple Module".
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| Illustration 16 | g00563390 |
If the "Module Status" LED is off, cycle the power and Refer to Troubleshooting, "Thermocouple Module".
Resistance Temperature Detector Module
The RTD module contains diagnostic features that can identify the source of the problems. The problems may occur during power up or during normal operation. The RTD module has three operational states. The operational states are in the following list: Power up, Operation of the module and Error.
Diagnostics
When you power up, a self-check is performed. The self-check is conducted of the RTD module. The self-check is of internal circuits, of memory, and of basic functions. During the check, the "Module Status" LED indicators are off.
If no faults are found during the power up diagnostics, the "Module Status" LED is illuminated.
When a channel bit is enabled, a diagnostic check is performed. The check verifies that the channel has been properly configured. In addition, the channel is tested for out-of-range and open circuit faults on every scan.
A failure of any channel diagnostic test causes the LED for the channel that has a fault to blink. All channel faults are indicated in bits 13 to 15.
The power up checks are complete. The RTD module waits for valid channel configuration data from your SLC ladder logic program. The "Channel Status" LED indicators are extinguished.
When a channel is read by the module, that data is tested by the module for a fault. If such a condition is detected the "Channel Status" LED flashes.
The RTD Module Fault Indicators
The RTD module has five LED indicators. Four of the LED indicators are "Channel Status" indicators. The "Channel Status" indicators are numbered according to the channel. One of the LED indicators is a "Module Status" indicator.
Diagnostics are displayed on the "Module Status" LED indicator. Operating errors are displayed on the "Module Status" LED indicator. Problems may be detected during powerup or problems may be detected during operation. When an error occurs, the module will not communicate with the processor. The channel is disabled and the data is cleared.
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| Illustration 17 | g00562942 |
"Channel Status" LED
The channel status LED indicators are used in order to indicate information of errors and channel status. This information is contained in the channel status word. You can recover from the channel errors. After corrective action, normal operation resumes.
The RTD Module Status LED
The module status LED indicators are used in order to indicate operating errors or module errors. You can not recover from the module errors. When an error is present, the RTD module no longer communicates to the processor. The channel states are disabled and the data words are cleared.
The RTD Module LED Indicators
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| Illustration 18 | g00563392 |
The "Module Status" LED is on. The "Channel Status" LED is flashing. Refer to Troubleshooting, "Resistance Temperature Detector".
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| Illustration 19 | g00563417 |
The "Module Status" LED is off. Cycle the power and refer to Troubleshooting, "Resistance Temperature Detector".
Modbus Module
The Modbus module allows an Allen-Bradley SLC 500 to interface with devices that are compatible with Modbus. The module allows a remote access to the MMS.
Port Information for the Modbus Module
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| Illustration 20 | g00563418 |
Information for port 1 is in the following list:
- RS-485
- 1 stop bit and no parity
- RTU slave
- Baud Rate from the "Setup" Screen
- Address from the "Setup" Screen
Information for port 2 is in the following list:
- RS-232
- 1 stop bit and no parity
- RTU slave
- Baud Rate from the "Setup" Screen
- Address from the "Setup" Screen
Jumper Settings for the Modbus Module
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| Illustration 21 | g00563421 |
Troubleshooting the Modbus Module
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| Illustration 22 | g00563423 |
| LED Name | Color | Status | Indication |
|---|---|---|---|
| CFG | Green | Off | The normal state of the LED. No configuration related activity is occurring. |
| Blink | The LED blinks every time the module configuration block (ID=255) is received from the processor ladder logic. | ||
| On | The LED is on continuously whenever a configuration error is detected. The error could be in the port configuration data or in the system configuration data. | ||
| BPLN | Red | Off | The normal state of the LED. When the LED is off and the "ACT" LED is blinking quickly, the module is actively transfering data with the SLC |
| On | The LED indicates that the block transfers between the SLC and the module have failed. | ||
| ACT | Green | Blink (fast) |
The normal state of the LED. The module is operating normally and successfully block transfering with the SLC. |
| On | The module is receiving power from the backplane, but there may be some other problem. | ||
| Blink (1/second) |
Indicated the module has somehow entered the basic programming mode. Verify the jumper JW3 (BAS only) configuration. If all are correct contact the factory. | ||
| Off | The module is attempting to block transfer with the SLC and has failed. The SLC may be in the PGM mode or may be faulted. | ||
| FAULT | Red | Off | The normal state of the LED. No system problems are detected during background diagnostics. |
| On | A system problem was detected during background diagnostics. Please contact the factory for technical support. | ||
| ERR1 ERR2 |
Amber | Off | The normal state of the LED. When the "ERR" LED is off and the related port is actively transfering data, there are no communication errors. |
| Blink | Periodic communication errors during data communications. | ||
| On | The LED will illuminate steady under several conditions: CTS input is not being satisfied. Port configuration error. System configuration error Unsuccessful communication on MCM slave Recurring error condition on MCM master |
||
| PRT1 PRT2 |
Green | Blink | The port is communicating, either transmitting or receiving data. |