PD8-6262 Explosion-Proof Dual Analog Input Flow Rate/Totalizer
Instruction Manual
26
RS-485 Connections
The RS-485 connections are made to a five terminal
connector used for Modbus
®
RTU serial
communications. The RS-485 terminals include
Transmit Data (DO) and (/DO), Receive Data (DI) and
(/DI), and Signal Ground. See
) on page
information.
There are three diagnostic LEDs: Transmit Data (TX),
Receive Data (RX) and METER LINK to show when
the totalizer is transmitting and receiving data from
other devices.
Figure 14. RS-485 Diagnostic LEDs
RS-485 Multi-Drop Connection
When using more than one totalizer in a multi-drop
mode, each totalizer must be provided with its own
unique address. The meter address (Slave ID) can be
programmed between 1 and 247. The transmit delay
can be set between 0 and 199 ms. The parity can be
set to even, odd, or none with 1 or 2 stop bits.
To change the meter address:
1. Press and hold the Menu button for three
seconds to access Advanced Features menu of
the totalizer.
2. Press Up arrow until Serial (
SEriaL
) menu is
displayed and press Enter,
Addres
is displayed.
3. Press Enter to change meter address using Right
and Up arrow buttons. Press Enter to accept.
4. Press Menu button to exit and return to Run
Mode.
Three-Wire Connection
In order to wire the five pins for use as a three-wire
half-duplex RS-485 connection, it is necessary to
create a jumper connection between DI to DO and /DI
to /DO- as shown below.
Figure 15. Three-Wire RS-485 Connection
__ __
DI
DI DO DO
