Resistor bridge

Notice

Measurement deviation due to incorrect shield connection

If you are using a shielded cable, grounding the cable shield at the sensor end can lead to measurement deviations.

  • Do not earth the cable shield at the sensor end.

The EP3356-0022 enables the connection of a resistor bridge or load cell in 4-wire technique.

Resistor bridge 1:

Connect the cable shield to pin 5 of the M12 connector.

The four M12 sockets of the EP3356-0022 are internally connected to one another. Therefore, you can connect a resistor bridge to any M12 socket.

You can also connect several resistor bridges in parallel, see chapter Parallel connection of strain gauges.

The voltage Uref is 10 V and is generated in the EP3356-0022 from UP.

Meaning of the LEDs

Resistor bridge 2:

LED

Color

Meaning

RUN

green

This LED indicates the operating state of the EtherCAT Box:

off

State of the EtherCAT State Machine: INIT = initialization of the EtherCAT Box.

flashing

State of the EtherCAT State Machine: PREOP = function of the mailbox communication and different default settings set.

single flash

State of the EtherCAT State Machine: SAFEOP = verification of the Sync Manager channels and the distributed clocks. Outputs remain in safe state.

on

State of the EtherCAT State Machine: OP = normal operating state; mailbox and process data communication is possible.

flickering

State of the EtherCAT State Machine: BOOTSTRAP = function for Firmware updates of the EtherCAT Box.

Stdy

green

on

The measured value is stable

off

The measured value is not stable

Msr

green

on

Measurement active (process data are valid)

off

  • Self-calibration active (when the LED S-Cal lights up) or
  • Self-test active (when the LED S-Test lights up)
  • Filters are initialized

S-Cal

green

on

Self-calibration active

  • The process data are not valid

S-Test

green

on

Self-test active

  • The process data are not valid

ErrD

red

on

Channel 1 (strain gauge differential signal) outside the valid value range.

ErrR

red

on

Channel 2 (strain gauge reference signal) outside the valid value range. Possible reasons:

  • The reference voltage Uref is not available. Check whether the supply voltage UP is present: Uref is generated internally from UP.
  • The reference voltage Uref has collapsed due to overload.