Beckhoff TwinSAFE User Manual download pdf (Page 136)

Circuit examples

134

Application Guide TwinSAFE

2.23 Direct wiring of the TwinSAFE outputs to TwinSAFE

inputs (2-channel) (Category 3, PL d)

Two outputs of an EL2904 are wired directly to two safe inputs of an EL1904; the test pulses and current

measurement of the outputs and the sensor test of the inputs are thereby deactivated. On the input side,

both signals are checked for discrepancy within the TwinSAFE logic. Hence, both signals are checked for

their value, but no tests are active on the cable, so that possible external feeds are detected when

switching the outputs.

2.23.1 Parameters of the safe input and output terminals

EL1904

Parameter Value

Sensor test channel 1 active No

Sensor test channel 2 active No

Sensor test channel 3 active No

Sensor test channel 4 active No

Logic channel 1 and 2 Single Logic

Logic channel 3 and 4 Single Logic

EL2904

Parameter Value

Current measurement active No

Output test pulses active No

2.23.2 Block formation and safety loops

2.23.2.1 Block 1

EL6900

EL2904

EL1904

EL2904

EL1904

1 2 ... 131 132 133 134 135 136 137 138 139 140

No comments

Beckhoff TwinSAFE User Manual Page 136