Panametrics Sentinel LCT, User Manual

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Sentinel LNG User’s Manual 167
Chapter 6. MODBUS Communications
Chapter 6. MODBUS Communications
6.1 Introduction
The Sentinel LNG supports digital communications using the MODBUS/RTU protocol, with 2-wire RS-485 or 3-wire RS-
232C as the physical layer. Data rate can be specified from 4800 to 19200 bits per second (bps), with selectable
parity.
6.2 Setting Up MODBUS Communications
1. To set up MODBUS Communications, from the main screen, use the arrow keys to scroll to [CONFIG]. Select
Communication and press ENTER, select Modbus and press ENTER. Nine options appear.
2. Address: To change the MODBUS address, use the arrow keys to select Address and press [ENT]. Use the arrow
keys to change the address number, and press [ENT] to save the change, or [ESC] to reject it. The screen returns
to the CONFIG menu.
3. Interface: To set the interface to be used, from the CONFIG menu select Interface and press [ENT]. Two options
appear: RS232 and RS485. Use the arrow keys to select the appropriate interface, and press [ENT]. The screen
returns to the CONFIG menu.
4. WordOrder: To set the word order, from the CONFIG menu select WordOrder and press [ENT]. Two options
appear: LowWordFirst and HighWord First. Use the arrow keys to select the appropriate order, and press [ENT]. The
screen returns to the CONFIG menu.
5. Baud Rate: To set the baud rate, from the CONFIG menu select Baud Rate and press [ENT]. Three options appear:
4800, 9600 and 19200. Use the arrow keys to select the appropriate option, and press [ENT]. The screen returns to
the CONFIG menu.
6. Parity: To set the parity, from the CONFIG menu select Parity and press [ENT]. Three options appear: None, Even
and Odd. Use the arrow keys to select the appropriate option, and press [ENT]. The screen returns to the CONFIG
menu.
7. Volumetric: To set the volumetric measurement, from the CONFIG menu select Volumetric and press [ENT].
Twelve options appear. Use the arrow keys to select the appropriate measurement type, and press [ENT]. The
screen returns to the CONFIG menu.
8. Total Units: To set the total units measurement, from the CONFIG menu select Total Units, and press [ENT]. Four
options appear: M
3
, Liters, Hectare-cm and Hectare-m. Use the arrow keys to select the appropriate
measurement type, and press [ENT]. The screen returns to the CONFIG menu.
9. StdVolumetric: To set the standard volumetric measurement, from the CONFIG menu select StdVolumetric and
press [ENT]. Twelve options appear. Use the arrow keys to select the appropriate measurement type, and press
[ENT]. The screen returns to the CONFIG menu.
10. StdTotal Units: To set the standard total units measurement, from the CONFIG menu select StdTotal Units, and
press [ENT]. Four options appear: M
3
, Liters, Hectare-cm and Hectare-m. Use the arrow keys to select the
appropriate measurement type, and press [ENT]. The screen returns to the CONFIG menu.
Modbus Communications are now set up and ready to use. Proceed to the following pages.