SDM-SW8A

Name: SDM-SW8A
Brand: Campbell Scientific
SKU: 4592
Availability: Discontinued

8-Channel Switch Closure Input Module

SDM-SW8A

Retired

8-Channel Switch Closure Input Module

No longer available to order

This product is retained for service, documentation, and compatibility information.

Replaced by

SDM-IO16A
16-Channel Input/Output Module

Model:: SDM-SW8A
Item Number:: 4592
Warranty:: 1 year

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.

Key Advantages

Expands Data Logger Input Channels
For switch closure or voltage pulse sensors

Technical 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.

Benefits

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

Specifications

Function: Increases the number of switch closures or voltage pulses a data logger can measure.
Number of Channels: 8
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: -25° to +55°C
Operating Voltage: 9.6 to 16 V
Typical Current Drain: 3 mA quiescent
6 mA active
(maximum)
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)

Accessories

(2)

Common Accessories

(1)

CABLE5CBL
5-Conductor 22 AWG Cable with Drain
This cable connects the SDM-SW8A to the datalogger. The CABLE5CBL-L is a 22 AWG, five conductor cable with a Santoprene jacket and an aluminum Mylar shield. A 1-ft cable length should be sufficient when both datalogger and SDM-SW8A are housed within an ENC12/14 enclosure; a 2-ft length may be required if the datalogger and SDM-SW8A are housed at opposite ends of an ENC16/18 enclosure.

CRBasic dataloggers should use the SDMSpeed instruction if the cable length is longer than 20 ft. The maximum recommended length for the CR7 is 600 ft. For other Edlog dataloggers, the maximum recommended cable length is 20 ft.
Orderable

Other Accessories

(1)

2206
22 AWG 3-Conductor Shielded PVC Cable
Typically, cabling is supplied as a part of the sensor or external device. If a cable is not provided, our 2206 three-conductor cable may suffice.
Orderable

Replacement Parts

(2)

Compatibility

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.