Connections in Detail
5-1
A minimal modem connection is thus GND, RX, TX, and either CD, or RTS and CTS.
Connecting RTS/CTS can help with modems that have hardware flow control turned on
by default. Preferably both CD and RTS/CTS should be connected.
See Figure 5-8 and Figure 5-9 for the location of the RJ45 connector. It is designated as
TB4.
RS-232 Active
The RS-232 port on the meter uses an RJ45 connector, which complies with the RS-
232D standard. To connect to a modem, use a modem with an RJ45 connector, or use
an RJ45 to DB9 adapter. RTS/CTS hardware handshaking is not supported. See Table
5-9 for connection details. Pin 1 of the RJ45 is on the right hand side.
RS232D RJ45
From Meter
RS232C DB9
To Modem
RS232C DB9
To PC (Null)
Description Full Name
TB3-1 * (9) (9) +12 +12V,3.6W output
TB3-2 Not Connected
TB3-3 Not Connected
TB3-4 5 5 GND Ground
TB3-5 2 3 RX Receive Data (to meter)
TB3-6 3 2 TX Transmit Data (from meter)
TB3-7 RX2 Receive Data–SCADA port
TB3-8 TX2 Transmit Data-SCADA port
• Table 5-9 RS-232 connections
* TB3-1 is connected to a +12V power source from the meter. This voltage is enough
for PSTN, GSM, and GPRS modems. It may vary up to 20V with loading.
See Figure 5-8 and Figure 5-9 for the location of the RJ45 connector. It is designated as
TB3.
TB3-7 and TB3-8 are present when a 3
rd
serial port option (SCADA port) is fitted to the
meter.
The Mk7C Meter 5-13