KROHNE BM 70 M - Manual (Page 30)

30 BM 70 M
PROFIBUS-PA / FF with current output: PROFIBUS-PA / FF with switching output:
7.7 Terminating resistor for the RS 485 interface
A selector plug on the RS 485 board allows
optionally a high-resistance termination (pre-
setting) or a terminating resistor of 120 Ohm at
the RS 485 connections A and B. For this
purpose, the housing (flameproof enclosure) of
the BM 70 M signal converter needs to be
opened (see Sect. 9.3) and the selector plug
turned 180°, see sketch on the right.
8 User interface
8.1 Local display
In the versions with local display at the BM 70 M signal converter, configuration can be carried
out directly at the device. If a local display is not featured, the PC-CAT program (see Sect. 8.12)
must be used to change the parameter setting (assuming a communicable interface is provided).
The available display is:
• Standard display with 2-line LCD display (7 mm high digits for the measured value).
Standard display
1 Numerical display of measured value
2 Alphanumeric display of function/unit
3 6 markers to indicate measuring status
4 3 keys for configuration and error inquiry
5 magnetic sensors for control through the
closed housing
(function same as the 3 keys)
6 Compass field, signals actuation of a key
42
-
Ex-i-supply-
+
+ unit
+
U max.= 30V
current
output
4-20mA
U min.
= 8V
41
-
32 31
Bus-
connection
32 31
switching output
max. 110mA/30V
42 41
Bus-
connection
120
Ω
RS485 signal-
output board
high-
impedance
....
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