69
LEVELtrol-II Installation & Operating Instructions
LEVELtrol-II RS-485 Port Pinout (recommended mating connector: DB-9M)
1 Ground
2 Ground
3 Ground
4 TX/RX (+)
5 TX/RX (-)
6 Do Not Use
7 Terminating Resistor (180 Ω)
8 TX/RX (+) (spare internally connected to 4)
9 TX/RX (-) (spare internally connected to 5)
LEVELtrol-II
RS-485 Port Pinout (Terminal Block Option)
1 Common
2 TX/RX (+)
3 TX/RX (-)
4 Terminating Resistor (180Ω)
Installation Overview
A two wire RS-485 may be multidropped up to 4000 ft. and up to 32 units may be chained together. A RS-
485 to RS-232 interface adapter is required at the PC. An optically isolated type is recommended. Suitable
wiring should be selected based on anticipated electrical interference. Terminators should be used to help
improve the quality of electronic signals sent over the RS-485 wires. The RS-485 chain should be terminat
-
ed at the beginning (RS-485 adaptor) and at the last device in the RS-485 chain and nowhere else. On the
LEVELtrol-II this is accomplished by connecting a jumper from terminal 7 to terminal 4 or 8 at the RS-485
port when DB-9 connector is used. Place jumper between terminals 2 and 4 when the terminal block option
is used. If lightning protection is required, a suitable surge protector should be used.
For additional information, refer to the technical requirements of EIA-485, interface adaptor user manual
and the communication software user manual
LEVELtrol-II Communication Setup Menu
The setup menu allows Modbus RTU Protocol communications parameters of: Device ID, Baud Rate, and
Parity to be selected to match the parameters of your RS-485 network. Each LEVELtrol-II must have it’s
own Device ID and the same Baud Rate and Parity setting.
1
2
3
4
5
6
7
8
9
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
RS-232
RS-485
1 2 3 4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
1
2
3
4
5
6
7
8
9
RS-232
RS-485
Appendix C - RS485 Modbus RTU Protocol
