Siemens SIMATIC ET 200iSP Operating Instructions Manual page 328

Digital electronic modules
13.2 Digital electronics module 4 DO
The WATCHDOG module can supply 2 mA current consumption each for up to 16 digital output
modules via one intrinsically safe contact K1 (e.g. Category 2G relay for installation in the
hazardous area Zone 1).
You do this by connecting the terminals of the intrinsically safe contact to the Pi terminal on the
WATCHDOG module and terminals 4/8 (+) of the digital output module.
Figure 13-8
Note
Only safety barriers with equipotential bonding are permitted!
Connect the safety barrier and the (last) digital output module controlled by the switching signal
securely to the equipotential bonding. With this wiring, all the chassis grounds of the outputs are
connected to the equipotential bonding.
See also
Pulling and plugging electronic modules during operation (hot swapping) (Page 227)
PROFIBUS interface module IM 152-1DP (Page 283)
328
Actuator disconnection with 11 V supply from the WATCHDOG module
Operating Instructions, 11/2022, A5E00247483-AK
ET 200iSP