Owner manual

LR4 Four Channel Latching Relay Module

6. LED Indicators

Five LEDs are on the control module. The main status LED indicates a

successful power up by turning on for one second. Rapid flashing for

approximately 3 seconds indicates a power-up problem. When the status LED

is on, any of the contacts that are in the 1 state will also have its LED on.

In normal operation, the status LED briefly flashes once every 5 seconds. Any

contact in the 1 state will have its LED flash with the status LED. A brief

button press can be used to activate the LEDs for a longer period of time to

observe the relay states. The button press must be less than 1 second to avoid

toggling any of the relays.

7. Using SDI-12

Contemporary dataloggers that support the SDI-12 protocol are the CR200X-

series, CR800, CR850, CR1000, CR3000, and CR5000. Retired dataloggers

that support the SDI-12 protocol include the CR200-series, CR510, CR10(X),

and CR23X.

7.1 SDI-12 Wiring

When the LR4 is controlled via the SDI-12 protocol, the RX/B terminal is not

connected. Often, the DIG I/O terminal is also not connected. The state of the

DIG I/O terminal can be read using SDI-12; it is meant to handle some custom

applications (contact Campbell Scientific for more information).

For SDI-12 communications, the CABLE3CBL three-conductor cable is

recommended to connect the LR4 to the datalogger when the DIG I/O port is

not used. The CABLE4CBL four-conductor cable is recommended when

using the DIG I/O port. Table 1 shows the datalogger connections.

Power-off the system before wiring the LR4.

CAUTION

TABLE 1. SDI-12 Wiring

LR4 Terminals Function Datalogger Terminal

GND

Power ground and

shield

POWER

Positive dc power

source (9-30 Vdc)

12V

SDI-12 /TX/A

SDI-12 signal Cx (control port)

RX /B

Not used Not used

DIG. I/O (optional) Readable digital input Cx (control port)

Where x is the control port number. Use the dedicated SDI-12 port on

CR5000 datalogger.

Where x is the control port number. Use of DIG I/O is for some custom

applications. Contact Campbell Scientific for more information.