FW-E112-P-MAN-EN_v0101_08
Page 35
Terminal C1-C4: type CB / CH - communication RS232 / RS485 (option)
Full serial communications and computer control in accordance with RS232 (length of cable max. 5
meters) or RS485 (length of cable max. 1200 meters) is possible.
Read the Modbus communication protocol and Appendix C.
C1
C2
C4
C3
RXD
TXD
A1
A2
ANALOG
OUTPUT
TYPE AH
RS485 - 2-wire
A
B
+
RS232
Fig. 14: Overview terminal connectors communication option.
When using the RS232 communication option, terminal C2 is used for supplying the interface. Please
connect the DTR (or the RTS) signal of the interface to this terminal and set it active (+12V). If no active
signal is available it is possible to connect a separate supply between terminals C1 and C2 with a voltage
between 8V and 12V.
Terminal A1-A2 analog output (SETUP 6):
An analog output signal proportional to the flowrate is available as standard.
Type AH
An isolated 4-20mA signal proportional to the flowrate is available with this option.
When the output is disabled, the current is by default limited to 3.5mA on these terminals.
Max. driving capacity 1000 Ohm @ 30VDC.
This loop can also be used to power the E112. If only powered by the loop the backlight will not be
activated.
EXTERNAL
INTERNAL
A1
A2
4-20mA
(<3.5mA when disabled)
Isolated 4-20mA analog output
