For dc devices with moderate current loads
Overview
The SDM-CD8S adds capability to a datalogger by controlling dc devices that have a moderate current load, such as solenoids, solenoid valves, dc motors, stepper motors, lights, horns, heaters, and fans. The SDM-CD8S is targeted for applications requiring only a few control ports and where a larger, high-powered relay module (such as the SDM-CD16S) is not necessary.
Read MoreBenefits and Features
- Provides a manual override
- Enables multiple SDM-CD8S devices to be wired to one data logger, increasing the number of devices that can be controlled
- Includes LEDs that provide a visual indicator of active outputs
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3D/CAD Files:
Technical Description
The SDM-CD8S has eight dc-voltage outputs and returns that can be switched on and off manually or under datalogger control. When the manual control switch is in the ON position, outputs are controlled by the position of the individual rocker switches. In the OFF position the state of the relays is controlled by the SDM commands from the datalogger.
The voltage range for this device is 8 to 26 Vdc. It can deliver up to 1 A per channel with a maximum of 6 A total for all channels. The power Input (8 to 26 Vdc) powers both the outputs and the SDM-CD8S logic.
SDM Operation
The SDM-CD8S is a synchronously addressed datalogger peripheral. Datalogger control ports 1, 2, and 3 are used to address the SDM-CD8S, then clock out the desired state of each of the 8 control ports. Up to 15 SDM-CD8S Controllers may be addressed, making it possible to control a maximum of 120 ports from the first three datalogger control ports.
Specifications
| Function | Allows the data logger to control dc devices that have a moderate current load, such as solenoids, solenoid valves, dc motors, stepper motors, lights, horns, heaters, and fans. |
| Number of Channels | 8 |
| Supply Voltage Range | 8 to 26 Vdc |
| Operating Voltage | 12 Vdc |
| Logic Current Drain (@ 12 Vdc) |
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| Toggle Switch |
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| Maximum Current |
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| Actuation/Release Times | 8 μs/200 μs |
| Operating Temperature | -40° to +70°C |
| Dimensions | 11.1 x 8.6 x 2.4 cm (4.4 x 3.4 x 0.9 in.) |
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) | ||
| CR200X (retired) | ||
| CR211X (retired) | ||
| CR211X (retired) | ||
| CR216X (retired) | ||
| CR216X (retired) | ||
| CR3000 (retired) | ||
| CR6 | ||
| CR800 (retired) | ||
| CR850 (retired) | ||
| CR850 (retired) | ||
| CR9000 (retired) | Although the CR9000 is compatible, the SDM-CD8S does not support its fastest communication rates and therefore is not practical for most of its applications. | |
| CR9000 (retired) | Although the CR9000 is compatible, the SDM-CD8S 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-CD8S 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-CD8S does not support its fastest communication rates and therefore is not practical for most of its applications. |
Miscellaneous
| Product | Compatible | Note |
|---|---|---|
| ENC10/12R | ||
| ENC16/18 | ||
| Granite 10 | ||
| Granite 6 | ||
| Granite 9 |
Additional Compatibility Information
Data Logger Considerations
Up to 15 SDM devices can be connected to a single data logger. 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.
Power Considerations
The SDM-CD8S power requirements may be large compared to most Campbell Scientific products. For most applications, an external power supply is recommended to power the SDM-CD8S.
For some applications, it may be convenient to use the data logger’s sealed-rechargeable battery. If the data logger’s rechargeable batteries are used, the batteries need to be float charged via a wall charger or solar panel. The current available from the wall charger limits the SDM continuous output current. Campbell Scientific does not recommend using the data logger’s alkaline power supply.
Enclosure Considerations
The SDM-CD8S 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.
Related Documents
Product Brochures
Case Studies
Related FAQs
Number of FAQs related to SDM-CD8S: 4
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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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Yes. Each of the channels on the SDM-CD8S and the SDM-CD16S has a manual control switch. Place the SDM-CD8S or SDM-CD16S into manual control by switching the Manual Control switch to the On position. Now each channel can be turned on or off using its respective switch.
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Yes. SDM devices are addressable. Multiple SDM devices can be connected to a datalogger, as long as they all have a unique SDM address. Valid addresses are 0 through 15. Address 16 is reserved for SDM devices that support the Group Trigger Command. The address is set using the rotary switch on the face of the SDM-CD8S or SDM-CD16S.
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The SDM-CD8S and SDM-CD16S were specifically designed to switch solenoids (inductive loads), similar to those found on valves. The diode, to protect against voltage kickback, is built into the device. The SDM-CD16AC, however, does not have this diode.
Case Studies
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