This product has limited availability. Some accessories, replacement parts, or services may still be available when it is no longer available.
Overview
The LR4 relay module is useful in situations where the power is unreliable or where power needs to be conserved, because it does not need electricity to keep the relay closed. The state of the relay can only be changed by sending a command to the LR4 or by manually toggling the relay button.
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Detailed Description
Unlike traditional relays that must be continuously powered to keep their state, the LR4 mechanically latches the relay’s state, allowing power to be removed. The only way to change the state of a relay is to send a command to the LR4 or to press the manual toggle button. The data logger sends commands to the LR4 via the SDI-12 protocol or ModBus protocol.
Specifications
| Function | Used in situations with unreliable power or where power needs to be conserved. |
| Number of Channels | 4 |
| Supply Voltage | 9 to 30 Vdc |
| Operating Voltage | 12 Vdc nominal (9 to 30 Vdc) |
| Operating Temperature | -40° to +60°C |
| Relay Type | Latching |
| Maximum Voltage Ratings of Relays | 30 Vdc/30 Vac |
| Dimensions | 17.0 x 3.7 x 6.1 cm (6.7 x 1.5 x 2.4 in.) |
| Weight | 0.48 kg (1.05 lb) |
Power Consumption |
|
| Quiescent | < 2.0 mA |
| Peak | < 250 mA |
Communications |
|
| Hardware | SDI-12, RS-232, RS-485 |
| Protocol | SDI-12 Version 1.3, or ModBus via RS-232/RS-485 at 19,200 bps |
Digital I/O Input Voltage |
|
| Maximum | +20 Vdc |
| Minimum | -12 Vdc |
Relay Contacts |
|
| Relay #1, Relay #2 | Two independent; single pole single throw (SPST) |
| Relay #3, Relay #4 | Two independent; single pole double throw (SPDT) |
Maximum Current |
|
| Relay #1, Relay #2 | Not to exceed 100 VA or 5 A |
| Relay #3, Relay #4 | Not to exceed 60 VA or 2 A |
Compatibility
Note: The following shows notable compatibility information. It is not a comprehensive list of all compatible or incompatible products.
Data Loggers
| Product | Compatible | Note |
|---|---|---|
| 21X (retired) | ||
| CR10 (retired) | ||
| CR1000 (retired) | ||
| CR10X (retired) | ||
| CR200X (retired) | ||
| CR206X (retired) | ||
| CR211X (retired) | ||
| CR216X (retired) | ||
| CR23X (retired) | ||
| CR295X (retired) | ||
| CR300 | ||
| CR3000 (retired) | ||
| CR310 | ||
| CR350 | ||
| CR500 (retired) | ||
| CR5000 (retired) | ||
| CR510 (retired) | ||
| CR6 | ||
| CR800 (retired) | ||
| CR850 (retired) | ||
| CR9000 (retired) | ||
| CR9000X (retired) |
Documents
Brochures
Downloads
LR4 OS v.1.3 (46 KB) 08-13-2014
Current LR4 firmware. Read the manual for the update procedure.
View Update HistoryFrequently Asked Questions
Number of FAQs related to LR4: 1
-
The following relay devices can be used with the CR800 and the CR850:
- 7321
- A6REL-12*
- A21REL-12
- LR4
- SDM-CD8S
- SDM-CD16AC
- SDM-CD16ACA
- SDM-CD16S
The CR800 and the CR850 can also be used with a wide variety of third-party relay devices.
*Because the CR800 and the CR850 only have four digital ports, they do not have the ability to switch all six of the relays on the A6REL-12.
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