FOXBORO P0916BX thermistor module

Description

P0914YM FCM10E
P0914YZ
P0916AA FBM201
P0916AC FBM202
P0916AE
P0916AE P0916FK-08
P0916AG
P0916BX

The FBM214 HART Communication Input Interface Module contains eight 4 to 20 mA group isolated analog input channels. The FBM214 supports any mix of standard 4 to 20 mA devices and HART devices. The FBM214 serves as a HART communications field device host, enabling the I/A Series system to request and receive two digital messages per second from the field device. The message pass-through capability can be used to support HART universal, common practice, and device-specific commands, but not the burst communication mode. These commands are implemented using the Intelligent Field Device Configurator (IFDC — refer to PSS 21S-8A3 B3 for details). The FBM214 provides a common isolated power supply to power all eight channels. Optionally, the channels can be powered by an external power supply. However, when a common external power supply is used with two or more channels, a Cable Balun module is required to prevent channel cross talk.

In the PLC system, there are several commonly used “grounding” related to grounding, which need to be handled separately according to different situations.

(l) Digital signal ground
Digital signal ground refers to the OV terminal of various switch quantities (digital quantities) in the system, such as the OV line of the proximity switch, the common OV of the PLC input, and the common OV of the transistor output.
In the PLC control system, digital signal grounding only needs to be connected according to the input/output connection method specified by the PLC in principle, without considering a special ground wire or connecting to the PE wire. Please refer to Section 7.3 “I/O Interface Design” of this book for details.

(2) Analog signal ground
Analog signal ground refers to the OV terminal of various analog quantities in the system, such as speed given voltage output for drivers (frequency converters), speed feedback input, sensor input, etc.
Analog signals usually use differential output/input, and the OV between each signal is independent. Therefore, it is generally not allowed to connect analog signals to each other or to the PE line of the system.
The connection line used for analog input/output should in principle use shielded “twisted pair” cables, and the shielding layer of the shielded cable must be connected to the PE line of the system according to different requirements.

(3) Protected area
Protective grounding refers to the grounding of the casings of various control devices and electrical equipment in the system, such as the protective grounding of motors and drivers. These protective grounds must be directly connected to the grounding busbar (PE busbar) inside the electrical cabinet, and PE wires of control devices and electrical equipment are not allowed to be “interconnected”.

(4) DC power supply ground
The system DC power source ground refers to the OV end of external DC power sources other than the internal power source of the PLC (the OV end of the internal DC power source of the PLC is generally shared with the digital signal ground of the PLC). It can be handled in the following situations:
① When the DC power supply for PLC input/output is separated, the OV of the DC power supply used for PLC input must be connected to the OV common line of the PLC according to the requirements of section 7.3 “I/O interface design” in this chapter. The DC power supply used for PLC output can be disconnected from the OV common terminal of the PLC or connected to the OV common terminal of the PLC as needed.
② When the PLC input/output DC power supply is shared, the OV of the DC power supply must be connected to the OV common line of the PLC. The DC power supply OV used for PLC input/output and the system grounding (PE) line can be connected or not according to the actual needs of the system.
③ The DC power supply OV used solely for the execution components of the PLC system is not connected to the OV of the PLC in principle, but generally needs to be connected to the grounding (PE) line of the system.
(5) AC power supply ground
AC power supply ground refers to the OV end (or N-line) of the AC power supply used in the system, such as the OV end of the 220V control circuit, the OV end of the AC lighting circuit, and the OV end of the AC indicator light.
When using isolation transformers in the AC control circuit, for the sake of “shock protection” and other considerations, in order for the transformer to play a “isolation” role, the OV end of the AC power supply should not be connected to the system grounding (PE) line in principle.

From the perspective of anti-interference, the PE line of the control system should not be connected to the N line of the power grid in principle. But on some imported machine tools, there are also cases where special “short circuiting terminals” are used to connect the OV end, N wire, and grounding (PE) wire of the AC power supply to each other.
PLC control systems usually belong to the category of low-frequency circuits below 1MHz, therefore, a “single point grounding” grounding method should generally be adopted.