OMC-042 / 043 / 044 Data loggers
Users
’ manual
page 45
Serial Port
The serial port of your data logger provides different forms of serial communications. This chapter
describes the details of this communication.
RS232
This mode allows to connect to RS232 sensors, see RS232 for details of the electrical properties.
Below a menu-settings screen is shown, for an RS232 sensor.
Generic Modbus/RTU
This is a versatile protocol that can be used with RS232, but you’ll encounter it more frequent with
RS485. Modbus/RTU is a compact binary protocol that is the factory standard for RS485
communications. So, when you use RS485, you can also select Modbus, in fact, it’s the only option for
RS485. Below the settings menu for Modbus / RTU is shown:
Port Settings
The user can select the right baud rate and Modbus Address of his sensor here. The address of the
sensor is very often adjustable, with the aid of a configuration tool of the sensor’s manufacturer. So, the
user can changed this according to its need. You can build a multi-sensor network, by using unique
addresses.
RS232 sensors
[0] Exit
[1] Generic MODBUS/RTU
[2] Generic Serial
[3] Generic NMEA
>
[0] Exit
[1] Name >> MODBUS/RTU
[2] Port settings >> RS232 8N1; 19200 Baud; Address 1
[3] Sensor power switch >> Enabled; Warm up 00:00:01
[4] Sample interval >> Data log interval
[5] Register type >> Holding
[6] Register start address >> 0
[7] Data type >> WORD (unsigned 2 bytes)
[8] Parameter 1 >> Not used
[9] Parameter 2 >> Not used
[A] Parameter 3 >> Not used
[B] Parameter 4 >> Not used
[C] Parameter 5 >> Not used
[D] Parameter 6 >> Not used
[E] Parameter 7 >> Not used
[F] Parameter 8 >> Not used
[G] Parameter 9 >> Not used
[M] More parameters >> Not used
[R] Remove
>