The A21REL-12 contains four internal relays that allow a Campbell Scientific datalogger to control up to four external ac or dc devices.
The A21REL-12's internal relays are single-pole double-throw. This relay driver may be powered by the datalogger power supply or a separate 12 Vdc battery.
Each of the four relays is controlled by a datalogger control port.
*The CR500 and CR510 only have one control port capable of providing a control signal.
|Cable(s) Used||Number of Relays Controlled|
The A21REL-12 may be powered by the datalogger power supply or a separate 12 Vdc battery.
The A21REL-12 requires a non-condensing environment. No mounting bracket is available. The peripheral is typically mounted in the datalogger enclosure with double-sided tape or Velcro.
Number of FAQs related to A21REL-12: 1
The following relay devices can be used with the CR800 and the CR850:
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 control ports, they do not have the ability to switch all six of the relays on the A6REL-12.