This product has limited availability. Some accessories, replacement parts, or services may still be available when it is no longer available.
For switch closure or voltage pulse sensors
Overview
Your data logger can measure more switch closures or voltage pulses with an SDM-SW8A. Sensors that output a switch closure or voltage pulse signal include tipping bucket rain gages, flow meters, and anemometers.
Read MoreBenefits and Features
- Well suited for use in energy management studies
- Provides eight individually configured channels
- Measures a variety of signals: reed switches, dry contacts, or slow voltage pulses
- Allows up to four SDM-SW8As to be connected to a single data logger
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Detailed Description
The SDM-SW8A provides eight channels for connecting the sensors. Each channel is individually configured for single-pole double-throw (SPDT), single-pole single-throw (SPST), or voltage pulse measurements. Output options include counts, duty cycle, and state.
SDM Operation
The data logger enables individual modules through an addressing scheme; multiple SDMs (in any combination) can be connected to one data logger. We recommend a maximum of four SDM-SW8As be connected to a single data logger. After a module is enabled, it operates independently of the data logger until additional commands are received or results are transmitted.
Specifications
| Measurement Types | Switch closure (SPDT, SPST), dc voltage pulse |
| Input Voltage Threshold | From below 0.9 to above 4.0 Vdc (±20 Vdc maximum) |
| Maximum Input Frequency | 100 Hz (50% duty cycle) |
| Minimum Input Pulse Width | 5 ms high, 5 ms low |
| Maximum Bounce Time | 3 ms open without counting |
| Output Options | State, duty cycle, counts |
| Maximum Count/Port | 65535 |
| Internal Sampling Frequency | 500 Hz |
| Watchdog Reset | Yes |
| Operating Temperature Range | -25° to +55°C |
| Operating Voltage Range | 9.6 to 16 V |
| Typical Current Drain |
|
| Relative Humidity | 0 to 90% RH (non-condensing) |
| Maximum Cable Length |
6 m (20 ft) total to all SDM devices Consult Campbell Scientific if longer lengths are necessary. |
| Dimensions | 15.7 x 6.9 x 2.3 cm (6.2 x 2.7 x 0.9 in.) |
| Weight | 0.23 kg (0.5 lb) |
Compatibility
Note: The following shows notable compatibility information. It is not a comprehensive list of all compatible or incompatible products.
Data Loggers
| Product | Compatible | Note |
|---|---|---|
| 21X (retired) | ||
| CR10 (retired) | ||
| CR1000 | ||
| CR1000X | ||
| CR10X (retired) | ||
| CR200X (retired) | ||
| CR206X (retired) | ||
| CR211X (retired) | ||
| CR216X (retired) | ||
| CR23X (retired) | ||
| CR295X (retired) | ||
| CR300 | ||
| CR3000 | For the CR3000, SDMs are connected to the ports labeled SDM-C1, SDM-C2, and SDM-C3. | |
| CR310 | ||
| CR500 (retired) | ||
| CR5000 (retired) | For the CR5000, SDMs are connected to the ports labeled SDM-C1, SDM-C2, and SDM-C3. | |
| CR510 (retired) | ||
| CR6 | ||
| CR800 | ||
| CR850 | ||
| CR9000 (retired) | ||
| CR9000X |
Mounting Equipment
| Product | Compatible | Note |
|---|---|---|
| ENC10/12 | ||
| ENC10/12R | ||
| ENC12/14 | ||
| ENC14/16 | ||
| ENC16/18 | ||
| ENC24/30 | ||
| ENC24/30S |
Additional Compatibility Information
Data Logger Considerations
Programming
In the CRBasic data loggers, the SDM-SW8A operation is controlled by the SDMSW8A instruction. Instruction 102 controls the SDM-SW8A operation for Edlog data loggers that were shipped after October 1988 (consult Campbell Scientific for equipment shipped prior to this date).
Power Supply
Due to the 3 mA continuous and 6 mA active current drain, an auxiliary 12 Vdc power supply is recommended for powering the SDM-SW8A in remote, long-term applications.
For some applications, it may be convenient to use the data logger power supply. You can do this where ac power is available, or where a solar panel can be used for recharging the data logger's sealed rechargeable battery.
Enclosure Considerations
The SDM-SW8A requires a desiccated, non-condensing environment; a Campbell Scientific enclosure is recommended. Grommets and screws are provided to attach the SDM-SW8A to the backplate of our enclosures.
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Cofely Fabricom NV/SA (GDFSuez) has utilized Campbell Scientific equipment on numerous projects in both the......read more
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