Campbell Scientific LR4 Four Channel Latching Relay Module - Manual (Page 15)

LR4 Four Channel Latching Relay Module
FIGURE 6. Communication Jumpers
8. Using Modbus
The LR4 can operate in a Modbus mode. The three internal jumpers in the
LR4 need to be moved from the SDI-12 position to either the RS-232 or the
RS-485 position for Modbus operation. By default, the LR4 is shipped with
the jumpers set for SDI-12 operation. The jumpers must be moved prior to any
connection with an RS-232 or an RS-485 device (see Section 8.1, Wiring for
Modbus). FIGURE 6. Communication Jumper shows the jumper positions on
the PCB.
To move the internal jumpers:
• Ensure that the LR4 is completely disconnected.
• Remove the cover of the LR4 by removing the two Philips screws.
8.1.1 RS-232
orted by the CR200(X), CR800, CR850, CR1000, and CR3000
dataloggers.
the LR4 to the datalogger. Table 2 shows the
datalogger connections.
ystem should be powered down before wiring the
8.1 Wiring for Modbus
RS-232 is supp
For the Modbus/RS-232 mode, the CABLE2TP 2-twisted pair cable is
recommended to connect
Your s
LR4. CAUTION
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