Dräger Polytron 7000 Instructions For Use Manual page 17

— Ensure that the supply voltage provided by the control unit (ignoring the
load resistance) is at least as high as specified in the tables of page 21 to
page 22.
— If digital communication in accordance with HART is to be used, the load
resistance of the supply unit must lie between 230 and 500
— The permissible cable lengths are shown in the tables on page 21 to
page 22. In each case, use the line marked "Number of transmitters = 1".
Ω.
Non-explosion-hazard area
Electrical connections
+
4 ... 20 mA
+
–
0 V
Control unit
17