Use multiple modules for up to 256 control ports
Overview
The SDM-CD16AC allows a Campbell Scientific datalogger to automatically activate external ac or dc devices such as motors, pumps, heaters, valves, and fans.
Read MoreBenefits 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
- Addresses up to 16 SDM-CD16ACs, allowing up to 256 ports to be controlled by one data logger
- Includes LEDs that indicate when a port is active
- Provides a manual override for each port
- UL/CUL approved product
Images
3D/CAD Files:
Technical Description
The SDM-CD16AC 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-CD16AC is a synchronously addressed data logger peripheral. Data logger control ports 1, 2, and 3 are used to address the SDM-CD16AC, then clock out the desired state of each of the 16 control ports. Up to 16 SDM-CD16ACs 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 |
|
| 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 |
|
| Normally Closed Rating |
|
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 |
|---|---|---|
| CR1000 (retired) | ||
| CR1000X | ||
| CR200X (retired) | ||
| CR216X (retired) | ||
| CR300 | ||
| CR3000 | ||
| CR3000 | ||
| CR310 | ||
| CR5000 (retired) | ||
| CR6 | ||
| CR800 | ||
| CR850 | ||
| 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. |
Miscellaneous
| Product | Compatible | Note |
|---|---|---|
| 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.
Resources and Links
Product Brochures
Downloads
SDM-CD16AC Program Examples v.1 (3 KB) 30-08-2021
There are three example programs for the CDM-CD16AC. The first program uses a counter to fill an array called srs() that will control two SDM-CS16ACs. 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.
FAQs for
Number of FAQs related to SDM-CD16AC: 4
Expand AllCollapse All
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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.
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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.
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Yes. Up to 15 SDM devices can be attached to a data logger 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.
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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 digital ports, they do not have the ability to switch all six of the relays on the A6REL-12.
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