17
modem operating with Modbus RTU prevents data link failure (over 1.5 times character length), i.e. the modem
task is to transmit a single data packet over the RS232/RS422/RS485 interfaces. The
Pause
option allows the
user to manually set the time interval of data absence, which will enable the modem to identify the end of data
package. Foremost, the Modbus RTU protocol is to be used if an external device operation is based on it.
Specify the
Modbus ASCII
protocol in the modem settings only if it is recommended to use this protocol by
the manufacturer of the external device.
2.10.3. Power Connector
Microfit 4 connector is used to connect power to the modem.
Fig. 2.6
Power Connector
Table 2.2
Power connector’s pin assignments
Pin
Signal
Function
1
Not used
2
Not used
3
GND
Negative terminal of power supply voltage
4
+ U
in
Positive terminal of constant power supply voltage. Protected by a
fuse and overvoltage (when applying voltage to input of over 40V)
and reverse polarity protection circuit
2.10.4. Terminal Connector (2GPIO+1GPO)
Fig. 2.7
Plug terminal connector
1
4
3
2
