Electrical Connection

FM502_CMS is plugged on the TF5x1_CMS together with PM592_ETH. The electrical connection is established using the terminals of the TF5x1_CMS. The FM502_CMS can be replaced without re-wiring the TF5x1_CMS TF501_CMS and TF521_CMS - Function Module Terminal Bases.

Warning

:strong:Removal/Insertion under power

The devices are not designed for removal or insertion under power. Because of unforeseeable consequences, it is not allowed to plug or unplug devices with the power being ON.

Make sure that all voltage sources (supply and process voltage) are switched off before you

• connect or disconnect any signal or terminal block
• remove, mount or replace a module.

Disconnecting any powered devices while energized in a hazardous location could result in an electric arc, which could create a flammable ignition resulting in fire or explosion.

Make sure that power is removed and that the area has been thoroughly checked to ensure that flammable materials are not present prior to proceeding.

The devices must not be opened when in operation. The same applies to the network interfaces.

Attention

:strong:Risk of damaging the PLC modules!

Overvoltages and short circuits might damage the PLC modules.

• Make sure that all voltage sources (supply and process voltage) are switched off before you begin with operations at the system.
• Never connect any voltages or signals to reserved terminals (marked with —). Reserved terminals may carry internal voltages.

Effect of incorrect input terminal connection

Wrong or no signal detected, no damage up to 35V

Connection of IEPE Sensors

Connection of IEPE sensor to the FM502_CMS

In order to avoid error messages or long processing times, we recommend to configure unused analog input channels as “unused”.

Note

For the open-circuit detection (cut wire) in IEPE mode, each channel is pulled up to the positive supply rail by a high impedance. If nothing is connected, the maximum value will be read FM502_CMS - Analog Measurements.

Connection of Active-Type Analog Sensors (Voltage) with Electrically Isolated Power\ Supply

Every negative analog input is internally connected to M (0 V) via an individual low impedance (PTC) return current path for the sensor supply current in IEPE mode. This is important for applications where a high input impedance on the negative analog input is required. Example: Stain gauges, bridge network.

Connection of Active-Type Analog Sensors (Voltage) with no Electrically Isolated\ Power Supply

Attention

Analog sensors should be electrically isolated against earth. In order to avoid inaccuracy with the measuring results, the analog sensors should also be isolated against the power supply.

Attention

If A- is not connected directly to M at the sensor, the supply current flows via A- to M. Measuring errors can occur caused by voltage differences between M and A-.

Attention

At system start up, the 4 mA current source on each analog input is active for < 10 s. During this limited time, a positive analog input will drift to < 21 V and no current is flowing, when a high impedance sensor is connected. When a low impedance sensor is connected to the analog input, the current is limited to 4 mA. For analog sensors other than standard IEPE, please make sure that the connected sensor will not be damaged under these conditions.

Analog signals must be laid in shielded cables. The analog cable shield must only be connected on the module side (SH terminals) to avoid relaxation currents influencing the measuring results, and for optimal robustness against external noise. The shield connection must be as short as possible (< 3 cm). The analog shield is capacitive coupled internally with functional earth (FE). Generally to avoid unacceptable potential differences between different parts of the installation, low-resistance equipotential bonding conductors must be laid.

In order to avoid error messages or long processing times, it is recommended to configure unused analog input channels as “unused”.

In order to avoid inaccuracy in the analog measurement, the FM502_CMS should be in thermal balance > 15 minutes after power up and start of the PLC application, before measurements are started.

Connection of Encoders with Differential RS-422 Signal

The encoder is powered by the 5 V power supply which is integrated in the FM502_CMS.

Connection of Encoders with 5 V TTL Signal

The encoder is powered through the 5 V power supply which is integrated in the FM502_CMS.

Connection of Encoders with 24 V Totem Pole Signal

The wires A-, B- and Z- must not be connected to the module for single-ended operation. They are left open.

When using different power supplies for the encoder device and the FM502_CMS, make sure that the reference potentials of both power supplies are interconnected.

Connection of Encoders with 1 Vpp Sine Signal

The encoder is powered by the 5 V power supply which is integrated in the FM502_CMS.

Connection of Absolute Encoders with RS-422 Differential SSI Interface

The encoder is powered by the 5 V power supply which is integrated in the FM502_CMS.

Connection of Absolute Encoders with Optical SSI Interface (optocoupler at\ CLK input)

The encoder can optionally be powered by the 5-V-power-supply which is integrated in the FM502_CMS.

Encoder/counter signals must be laid in shielded cables. The cable shield must be earthed at both sides of the cable. In order to avoid unacceptable potential differences between different parts of the installation, low-resistance equipotential bonding conductors must be laid. Only for applications with low disturbance and/or cables length < 30 m the shield might be omitted.

Note

The 5 V output provides a current of 100 mA max.

Attention

:strong:Risk of damaging the FM502_CMS!

The 5 V output has no protection against reverse polarity.

Connection of Standard Inputs/Outputs

Connection of Sensors with Frequency Outputs

Example for electrical connection of sensors with frequency outputs to the input Z+