Siemens SIMATIC NET PROFIBUS Connecting the power supply, Connecting the signaling contact lines

4 Setting Up 4.4 Installation

4.4.4 Connecting the power supply

L1+ / +24 V

F1

M /

F2

L2+ / +24 V*

Fig. 10: Operating voltage supply – assignment of 5-pin terminal block

The terminal block can be removed from the device to connect the lines.

The module should only be supplied with a regulated safety extra-low voltage in accordance with IEC 950/EN 60 950/VDE 0805 with a maximum of +32 V (typical +24 V). The power source must comply with the regulations of the NEC, Class 2 in accordance with UL/CSA approval.

It can be fed in using the 5-pin terminal block on the top of the module.

To increase operational safety, the module can be redundantly supplied via the terminals L2+/+24 V* and M/m.

In the event of a failure of the regular power supply, the module switches automatically to the redundant power supply. Load distribution between the individual alter- native supply sources does not take place.

The signaling contact does not signal the failure of a single 24 V infeed. Both of the infeeds and the signa- ling contact must be connected to an input module for monitoring to take place.

Clips on the terminal block ensure that it is securely attached to the device, and simultaneously provide polarity reversal protection.

4.4.5 Connecting the signaling contact lines

F1F2

Fig. 11: Signaling contact - relay with unconnected contacts; the contact is open if a fault occurs

The terminal block can be removed from the device to connect the lines.

A relay with unconnected contacts as signaling contacts is fitted to the 5-pin terminal block on the top of the module. This signals faults and interference in the network and modules. The contact is open if a fault occurs. This also signals a total loss of power at the module.

Refer to Chapter 5.1 ”LED indicators“ p. 25 for more details about malfunctions which are signaled by the signaling contact.

Signaling contact limit values:

–maximum switching voltage 60 V DC; 42 V AC

– maximum switching current 1.0 A

The voltage connected to the relay must be regulated safety extra-low voltage in accordance with IEC 950/EN 60 950/ VDE 0805 and must comply with the regulations of the NEC, Class 2 in accordance with UL/CSA approval.

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