Analog input (4-20 mA): Supports two-wire (loop power supply) or four wire (self powered) transmitters. Attention should be paid to whether a common terminal jumper needs to be installed when wiring. The input impedance is 200 Ω.
Analog output (4-20 mA): The maximum driving capacity is 600 Ω load. Output non isolated, attention should be paid to the grounding loop.
Output of actuator: It can be configured to drive single coil or double coil actuators, with an output range of 4-20 mA or 20-160 mA. When wiring, specified jumpers need to be installed or removed according to the configuration.
Discrete (contact) input: 24 inputs, of which 4 have fixed functions (external emergency stop, reset, speed up, speed down). The contact wetting voltage can be provided by internal 24 Vdc, external 18-32 Vdc, or 100-150 Vdc (UL only). When using the internal power supply, jumper wires need to be installed on the DTM.
Relay output: 12 outputs, of which 2 have fixed functions (shutdown relay, alarm relay). Each route consists of 6 relays in series and parallel to achieve fault tolerance and latent fault detection.
LFD configuration: LFD is only suitable for circuits with 18-32 Vdc, 88-132 Vac, or 100-150 Vdc. It will inject a small leakage current into the load to detect faults when the relay is disconnected. It is necessary to verify whether the leakage voltage on the load is lower than its release voltage through the curves in Figures 4-10 to 4-12, otherwise LFD or parallel shunt resistor should be disabled.
Jumper setting: Each relay output requires two sets of jumpers: one set selects the circuit voltage to match the LFD logic, and the other set selects whether to detect normally open (NO) or normally closed (NC) contacts. It is recommended to use internal 24 Vdc for the relay coil power supply.
4.4 Communication and System Power on
Serial communication: The system provides multiple RS-232/422/485 ports for connecting engineering workstations (PCI), Modbus devices, printers (connected to CPU-B or SIO Port 1), OpView, etc. The communication distance of RS-232 is limited to 15 meters, and longer distances require the use of RS-422/485 or a converter.
System power on:
Turn on both main power sources in sequence and confirm that only the green "OK" LED is lit.
Instantly turn the "Reset/Run" switch of the A, B, and C core CPUs to the reset position and then turn it back.
The system will perform offline diagnosis (taking several minutes). After completion, all CPU red fault lights should turn off, green running lights should turn on, and the application program will start running.
Warning: Before starting the turbine for the first time, it is necessary to verify the calibration of all external input and output devices.
Chapter 5: Troubleshooting and Module Replacement
This chapter provides detailed LED status instructions, diagnostic procedures, and module replacement steps.
5.1 Key points for module diagnosis and replacement
Main power module: The status is indicated by the front panel LED (normal, input fault, overheating, power fault). When replacing, the input power must be disconnected first.
Kernel power module: Before replacement, it is necessary to use an engineering workstation to confirm that other kernels are running normally, then reset the CPU of that kernel, and first unplug all other modules in that kernel before replacing the kernel power supply.
CPU module: indicates status through running, I/O lockout, low VCC, and watchdog LED. Before replacing, confirm that other CPUs are functioning properly, reset the target CPU, disconnect the communication cable, and then replace.
I/O module (analog/discrete): The fault LED is constantly on or flashing, indicating a module fault. Key steps for hot plugging: First, release the module to disconnect it from the motherboard but still plug it into the slot, then disconnect the I/O cable and remove the faulty module; When installing a new module, first insert the module (without forcefully pressing it to the bottom), connect the I/O cable, and finally fully press the module into the motherboard socket and tighten it. This sequence can avoid system tripping caused by pin short circuits.
Terminal module (ATM/DTM): It is recommended to replace it when the system is offline. The fuse (24 Vdc/0.1 A) on the ATM can be replaced online. When replacing DTM relays, be sure to pay attention to high voltage hazards.
5.2 System Diagnosis
Offline diagnosis: Execute after CPU reset to detect core hardware such as memory, communication, clock, etc. The fault is represented by the flashing frequency code of the CPU fault LED (Table 5-1).
Online diagnosis: continuous during runtime, detecting task timeouts, memory errors, etc. The fault information is displayed in the OpSys fault mode of the engineering workstation (Table 5-2).
5.3 Comprehensive Investigation Guidelines
The manual provides a comprehensive system troubleshooting checklist (pages 79-80), covering various aspects such as actuators, linkage mechanisms, valves, oil circuits, steam conditions, input/output signals, sensors, power supplies, wiring, external devices, etc. It is a valuable tool for systematic fault location.