RETIRED ›
This product is no longer available and has been replaced by: SDM-CD16ACA. Some accessories, replacement parts, or services may still be available.
SDM-CD16AC 16-Channel AC/DC Relay Controller
Services Available
Repair Yes
Calibration Yes
Free Support Yes

Overview

The SDM-CD16ACA allows a Campbell Scientific datalogger to automatically activate external ac or dc devices such as motors, pumps, heaters, valves, and fans.

Read More

Benefits and Features

  • Allows the data logger to automatically turn devices on or off when a threshold (for example, temperature or water depth) has been reached
  • Includes LEDs that indicate when a port is active
  • Provides a manual override for each port
  • UL/CUL approved product
  • Addresses up to 15 SDM-CD16 ACAs, allowing up to 240 ports to be controlled by one datalogger

Images

Technical Description

The SDM-CD16ACA has a toggle switch that provides three positions: ON and OFF for manual override, and AUTO for data logger control.

  • In the ON position, the common (COM) and normally open (NO) contacts are closed.
  • In the OFF position, the normally open contact is open.
  • In the AUTO position, the state of the relay is controlled by the SDM command issued through the data logger’s control ports or SDM terminal.

SDM Operation

The SDM-CD16ACA is a synchronously addressed data logger peripheral. Data logger control ports 1, 2, and 3 are used to address the SDM-CD16ACA, then clock out the desired state of each of the 16 control ports. Up to 16 SDM-CD16ACAs may be addressed, making it possible to control a maximum of 256 ports from the first three data logger control ports.

Specifications

Function Allows a data logger to automatically activate external ac or dc devices such as motors, pumps, heaters, valves, and fans.
Number of Channels 16
Operating Temperature -40° to +55°C
Humidity Non-condensing
Contact Operation Single pole double throw (break before make)
Contact Material Gold-clad silver
Coil Voltage 11 to 18 Vdc
Coil Resistance 360 Ω ±10%
Expected Life (contact closures) Mechanical 107
Actuation/Release Time ~4 ms
Toggle Switch
  • ON/OFF manual override
  • AUTO for data logger control
Operating Voltage 12 Vdc nominal (11 to 18 Vdc)
Standards Underwriters Laboratories (UL) listed product (E162021)
Dimensions 24.6 x 5.1 x 8.6 cm (9.7. x 2.0 x 3.4 in.)
Weight 0.8 kg (1.8 lb)

Individual Contact Ratings

Normally Open Rating
  • 5 A (@ 30 Vdc)
  • 5 A (@ 125 Vac)
  • 5 A (@ 250 Vac)
Normally Closed Rating
  • 1 A (@ 30 Vdc)
  • 3 A (@ 125 Vac)
  • 2 A (@ 250 Vac)

Current Drain @ 12 Vdc

Quiescent 6 mA
Per Active LED 45 mA (switch on or auto active)

Compatibility

Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.

Dataloggers

Product Compatible Note
21X (retired)
CR10 (retired)
CR1000 (retired)
CR1000X
CR10X (retired)
CR200X (retired)
CR211X (retired)
CR216X (retired)
CR23X (retired)
CR300
CR3000 (retired)
CR310
CR350
CR500 (retired)
CR5000 (retired)
CR510 (retired)
CR6
CR800 (retired)
CR800 (retired)
CR850 (retired)
CR850 (retired)
CR850 (retired)
CR850 (retired)
CR9000 (retired) Although the CR9000 is compatible, the SDM-CD16AC does not support its fastest communication rates and therefore is not practical for most of its applications.
CR9000X (retired) Although the CR9000X is compatible, the SDM-CD16AC does not support its fastest communication rates and therefore is not practical for most of its applications.

Mounting Equipment

Product Compatible Note
ENC10/12
ENC12/14
ENC14/16

Miscellaneous

Product Compatible Note
ENC10/12R
ENC16/18
Granite 10
Granite 6
Granite 9

Additional Compatibility Information

Data Logger Considerations

Up to 16 SDMs can be connected to our data loggers. To communicate with connected SDM devices, the CR3000 and CR5000 use the SDM-C1, SDM-C2, and SDM-C3 ports. The other data loggers use ports labeled C1, C2, and C3. The 21X also requires channel 1H.

Programming

The SDMCD16AC Instruction controls SDM-CD16AC operation in CRBasic. Edlog Instruction 29 controls SDM-CD16AC operation in the CR7, and Edlog Instruction 104 controls SDM-CD16AC operation in the CR10(X), CR23X, and 21X data loggers.

Power Considerations

The data logger's rechargeable power supply, connected to our newer 1.2 A wall charger, is sufficient for powering the SDM-CD16AC. The SDM-CD16AC's LEDs consume 45 mA each when active. If all 16 LEDs are active at once, a current drain of over 720 mA should be expected. If more than one SDM-CD16AC will be used, a deep-discharge external battery may be necessary. This external battery should share a common grounding point with the data logger's ground.

Campbell Scientific does not recommended using the data logger’s alkaline batteries to power the SDM-CD16AC for long-term applications.

Enclosure Considerations

The SDM-CD16AC requires a desiccated, non-condensing environment; a Campbell Scientific enclosure is recommended. Grommets and screws are provided to attach the flanges/bracket to the backplate of our enclosures.

Downloads

SDM-CD16AC Program Examples v.1 (3 KB) 11-04-2022

There are three example programs for the CDM-CD16AC. The first program demonstrates using two SDM-CD16AC modules to control pumps and heaters based on water level and temperature thresholds. The remaining two programs are designed to control the temperature in five greenhouses. The temperature will be maintained between 23 and 28 °C in each greenhouse. In each greenhouse, the SDM-CS16AC controls a heating unit, a refrigerating unit, and an air-mixing fan according to these conditions.  

Heating unit: Activate when temperature < 23.5 °C. Deactivate when temperature > 25.5 °C

Cooling unit: Activate when temperature > 27.5 °C. Deactivate when temperature < 24.5 °C

Mixing fan: Activate whenever the heating or cooling units are activated. Activate for 5 minutes out of every 15 minutes.

The difference between program 2 and program 3 is the method used to control outputs. Program 2 uses an array to set the SDM-CD16AC outputs. Program 3 uses a Long integer, with each bit in the variable controlling one of the outputs.

Related FAQs

Number of FAQs related to SDM-CD16AC: 4

Expand AllCollapse All

  1. No. The SDM-CD16S was designed to switch dc loads (7 to 48 Vdc; 2 A maximum per channel). The load power is isolated from the logic power (12 Vdc).

    To switch an ac load, consider using an SDM-CD16AC.

  2. No. The SDM-CD8S was designed to switch dc loads (12 Vdc nominal; 1 A maximum per channel, total current on all channels not to exceed 6 A). The SDM-CD8S switches the - outputs, rather than the + output. This is called a low-side switch. The + output is the same voltage as the PWR used to power the SDM-CD8S to ground.

    To switch an ac load, consider using an SDM-CD16AC.

  3. The following relay devices can be used with the CR800 and the CR850:

    • 7321
    • A6REL-12*
    • A21REL-12
    • LR4
    • SDM-CD8S
    • SDM-CD16AC
    • 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 control ports, they do not have the ability to switch all six of the relays on the A6REL-12.

  4. Yes. Up to 16 SDM devices can be attached to a datalogger because they are addressable with a hex number of 0 to F.  Some of those devices may require more power, which would need to be considered when adding devices.

Case Studies

New Mexico: SCADA System
In April of 2015, Sandia National Laboratories (SNL) contracted with Montrose Air Quality Services (MAQS)......read more
New Jersey: Pequest Trout Hatchery
Moving clean, cold water through a trout-rearing facility is essential to its success. A live......read more
Australia: OzFace—Carbon Dioxide and Climate Change
An experimental facility (OzFace) has been established in Townsville, Australia, to examine the impacts of......read more
California, Stolt Sea Farm: Caviar Aquaculture
In August 1996, Stolt Sea Farms installed a Campbell Scientific monitoring and control system at......read more
Mississippi, Lee's Catfish Farm: DO Monitoring & Control
Since 1996, Levi Lee and his son Jeff have used a Campbell Scientific measurement and......read more