FOXBORO FBM204 P0917QY-0C controller

Description

Modular Baseplate Mounting

The modules mount on a DIN rail mounted modular baseplate, which accommodates up to 16 compact FBMs. The baseplate is either DIN rail mounted or rack mounted, and includes signal connectors for redundant fieldbus, redundant independent DC power, and termination cables.

Fieldbus Communication

A Fieldbus Communications Module or a Control Processor interfaces to the redundant 2 Mbps module Fieldbus used by the FBMs. The FBM accepts communication from either path (A or B) of the 2 Mbps Fieldbus. If one path is unsuccessful or is switched at the system level, the module continues communication over the active path.

In order to facilitate the timely resolution of PLC faults, it is first necessary to distinguish whether the fault is global or local. For example, if the upper computer displays multiple control components that are not working properly and prompts many alarm messages, it is necessary to check the common parts such as the CPU module, memory module, communication module, and power supply. If it is a localized fault, it can be analyzed from the following aspects. 1. Find faults based on the alarm information of the upper computer.

PLC control systems all have rich self-diagnosis functions. When a system malfunctions, an alarm message is immediately given, which can quickly and accurately identify the cause and determine the fault location. It has the effect of twice the result with half the effort and is the basic means and method for maintenance personnel to troubleshoot. 2. Diagnose faults based on the sequence of actions
For automatic control, its actions are completed in a certain order. By observing the system’s movement process, comparing faults with normal conditions, suspicious points can be identified and the cause of the fault can be diagnosed. If a certain water pump requires both front and rear valves to be opened in order to start, the water pump cannot be started if the pipeline is not connected. 3. Diagnose faults based on the status of PLC input and output ports.

In the PLC control system, the transmission of input and output signals is achieved through the I/O module of the PLC, so some faults will be reflected on the 1/0 interface channel of the PLC, which provides convenience for fault diagnosis. If it is not a hardware fault of the PLC system itself, there is no need to check the program and relevant circuit diagrams. By querying the I/O interface status of the PLC, the cause of the fault can be identified. Therefore, it is necessary to familiarize oneself with the normal I/O status and fault status of the PLC controlling the object. 4. Diagnose faults through PLC program.

The vast majority of faults in the PLC control system are detected through PLC programs. Some faults can directly display the alarm reason on the screen; Some may have alarm messages on the screen, but they do not directly reflect the cause of the alarm; Some faults do not generate alarm messages, but some actions are not executed. Tracking the operation of the PLC program is an effective method for diagnosing faults in the latter two situations. For simple faults, the status display information of the PLC can be used to monitor the status of relevant inputs, outputs, and flag bits, and track the operation of the program. For complex faults, a programmer must be used to track the operation of the program. If a certain water pump does not work, it is found that the corresponding PLC output port is 0. Therefore, by checking the program, it is found that the hot water pump is still controlled by the water temperature. If the water temperature is not enough, the PLC will not output. After the water temperature rises, the fault is resolved. Of course, the above methods only provide a starting point for fault resolution. There are many reasons for faults, so relying solely on a certain method cannot achieve fault detection. Multiple methods need to be combined, combined with comprehensive analysis of circuits, machinery, and other parts.