The SDM-AO4A includes four independent, continuous, analog outputs (CAO), which are used for proportional control or driving strip charts. Measured or processed values in the data logger are scaled to millivolts and transferred to the SDM-AO4A as digital values. The SDM-AO4A then performs a digital to analog conversion and outputs an analog voltage signal.Read More
The SDM-AO4A is designed to output four continuous voltages at levels set by a Campbell Scientific data logger. The data logger enables individual modules through an addressing scheme; multiple SDMs (in any combination) can be connected to one data logger. After a module is enabled, it operates independently of the data logger until additional commands are received or results are transmitted.
The SDM-AO4A can be operated in ±5 V mode or 10 V mode. In each of these modes, the SDM-AO4A can operate synchronously or sequentially. In synchronous mode, all channels are set at the same time.
|Function||Increases the number of continuous analog output (CAO) ports available to a data logger. CAOs are used for proportional control or driving strip charts.|
|Number of Channels||4|
|Operating Temperature||-40° to +60°C|
|Voltage Range||±5 V or 0 to 10 V|
|Operating Voltage||12 Vdc nominal (9.6 to 16 Vdc)|
|Maximum Output Current||
|Overcurrent Shutdown Point||130 mA ± 15 mA|
|Dimensions||13.46 x 8.51 x 2.41 cm (5.3 x 3.35 x 0.95 in.)|
|Weight||175 g (6.2 oz)|
Accuracy with 20 kΩ Load (maximum)
|25°C||±(0.05% of |Vout(V)|+500µV)|
|-40° to +60°C||±(0.1% of |Vout(V)|+500µV)|
Additional Full-Scale Error with 50 mA Load
|±5 V Mode||-1.3 mV (typical)|
|0 to 10 V Mode||-1.5 mV (typical)|
Typical Current Drain (±5 V Mode)
|No load, Vout=0, Vsupply=12V||11 mA|
|No load, Vout=fullscale, Vsupply=12V||13 mA|
|With load, Vsupply=12V||13 mA + load|
|Power Down Mode, Vsupply=12V||1.1 mA|
Typical Current Drain (0 to 10 V Mode)
|No load, Vout=0, Vsupply=12V||21 mA|
|No load, Vout=fullscale, Vsupply=12V||28 mA|
|With load, Vsupply=12V||28 mA + (2.4)(load)|
|Power Down Mode, Vsupply=12V||1.1 mA|
Note: The following shows notable compatibility information. It is not a comprehensive list of all compatible or incompatible products.
|21X (retired)||Edlog data loggers only support the ±5 V mode and synchronous operation.|
|CR10 (retired)||Edlog data loggers only support the ±5 V mode and synchronous operation.|
|CR10X (retired)||Edlog data loggers only support the ±5 V mode and synchronous operation.|
|CR23X (retired)||Edlog data loggers only support the ±5 V mode and synchronous operation.|
|CR3000 (retired)||For the CR3000, SDMs are connected to the ports labeled SDM-C1, SDM-C2, and SDM-C3.|
|CR5000 (retired)||For the CR5000, SDMs are connected to the ports labeled SDM-C1, SDM-C2, and SDM-C3.|
Up to 15 SDM devices can be connected to a single data logger.
It may be convenient to use the data logger’s batteries to power the SDM-AO4A, but consideration must be given to the SDM-AO4A’s continuous current drain (11 mA in ±5 V mode or 21 mA in 10 V mode). The data logger’s alkaline batteries can power one SDM-AO4A for less than a month, and therefore these batteries are not recommended for continuous long-term operation. The data logger’s sealed rechargeable batteries, float charged by an ac supply or solar panel, typically can be used for long-term operation.
The SDM-AO4A may also be powered from an external 12 Vdc source, independent from the data logger batteries. The low side of this external 12 Vdc source needs to be connected to data logger ground and not directly to earth ground.
The SDM-AO4 requires a desiccated, non-condensing environment; a Campbell Scientific enclosure is recommended. The SDM-AO4A has built-in keyhole flanges for mounting to the backplates of Campbell Scientific enclosures. Grommets and screws are provided to attach the flanges/bracket to the backplate of our enclosures.
Number of FAQs related to SDM-AO4A: 4
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For the CR1000, to get continuous analog outputs, an SDM-AO4A (4-channels, non-isolated, voltage only) or an SDM-CVO4 (4-channels, isolated, voltage or current) is needed. Multiples of these devices can be used to get more outputs. For single channels of output, some third-party devices can be used.