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SDM-CVO4 4-Channel Current/Voltage Output Module 

The SDM-CVO4 is a synchronously addressed datalogger peripheral. The 
datalogger’s SDM ports are used to address the SDM-CVO4 and send out data 
that defines the desired voltage/current output of each of the four channels. 
The output levels are set by four values stored in variables or successive input 
locations in the datalogger. A total of up to sixteen SDM-CVO4s or other 
SDM peripherals may be connected and addressed from the same three ‘SDM’ 
ports. 

For the CR7, CR10(X), CR23X, and 21X dataloggers Instruction 
103 is used to control the SDM-CVO4. This was introduced in 
August 1988 for controlling SDM-AO4 functions. (The SDM-
AO4 is an older voltage-output-only peripheral.)  Dataloggers 
purchased before this date may use a different instruction.  

NOTE 

The SDMCVO4 instruction is used with the CR800, CR850, 
CR1000, CR3000, and CR5000.  

2.  Specifications 

2.1  General Specifications 

Compatible dataloggers

CR800, CR850, CR1000, CR3000, CR5000, and 
CR7.  Also compatible with many retired 
dataloggers such as the CR10, 21X, and CR23X. 

Operating voltage

:  

12 VDC nominal (8 V to 16 V) 

Current drain at 12V DC

:  Typical active quiescent current 27 or 54 mA, 

depending on operating mode (no load on output 
ports). To estimate the total current, add the 
quiescent current to the sum of all output currents 
multiplied by 1.5. 

 

E.g. if each port is at 10 mA output, the total = 
54 + (1.5*4*10) = 114 mA. The device can be 
shut down to <0.5 mA with all outputs off. 

Maximum Total 
SDM cable length: 

600 ft (182 m) for the CR7; 20 ft (6 m) for other 
dataloggers if the SDMSpeed Instruction is not 
used.  For our CR800, CR850, CR1000, 
CR3000, and CR5000 dataloggers, cable lengths 
longer than 20 ft may be acceptable if the 
SDMSpeed instruction is used. 

Operating temperature:

   -25

°

C to +50

°

C standard (-40 to 80

°

C optional) 

Size:

 

176 mm wide x 111 mm high x 24 mm deep. 

 

234 mm wide x 111 mm high x 24 mm deep 
when fitted with brackets for mounting in 
enclosure, etc. Mounting brackets have two holes 
at 203.2 mm (8") spacing for screw fixings.  

Содержание SDM-CVO4

Страница 1: ...SDM CVO4 4 Channel Current Voltage Output Module Revision 7 11 C o p y r i g h t 2 0 0 1 2 0 1 1 C a m p b e l l S c i e n t i f i c I n c...

Страница 2: ...IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE Campbell is not liable for any special indirect incidental and or consequential damages Products may not be returned without p...

Страница 3: ...ode Setting 8 4 4 SDM Address Setting 9 4 5 Safety Considerations 10 5 General Principles of Use 12 5 1 Voltage or Current Signaling 12 5 2 Providing Excitation Supplies to Sensors 12 6 Datalogger Pro...

Страница 4: ...SDM CVO4 Table of Contents ii Tables 4 1 Datalogger to SDM CVO4 Connections 4 4 2 Switch Position and Addresses 10 6 1 Description of SDM Speed 16 6 2 Description of Instruction 103 17...

Страница 5: ...d by the application Typical applications will include driving remote current loop display units re transmitting measured values to industrial control systems which have current or high voltage inputs...

Страница 6: ...ecifications Compatible dataloggers CR800 CR850 CR1000 CR3000 CR5000 and CR7 Also compatible with many retired dataloggers such as the CR10 21X and CR23X Operating voltage 12 VDC nominal 8 V to 16 V C...

Страница 7: ...lating circuit 2 5 V at 20 mA current flow Maximum voltage into Id relative to channel ground 20 VDC When in current mode the Vo terminal outputs an unregulated voltage source at 15 V nominal 10 30 mA...

Страница 8: ...y 20 mA lower than when all outputs are used Where supported by the datalogger and when the application allows it the SDM CVO4 can be shut down to reduce its consumption to less than 0 5 mA In this st...

Страница 9: ...Make sure the ground wire from the SDM CVO4 to the datalogger goes to its G terminal and not the AG terminal The SDM CVO4 uses spring loaded terminal blocks for the connections to the datalogger whic...

Страница 10: ...C power source in current mode In voltage mode the connection to a remote device is a simple two wire connection Inputs Remote Voltage Input CVO4 Vo 4 2 2 Current Output Mode The Id terminal acts as t...

Страница 11: ...nse resistor this will drop 5V at 20mA using Ohm s law which in addition to the SDM CVO4 s 2 5 V drop in the loop means the maximum allowable voltage drop in the cable of the loop should be 13 5 5 0 2...

Страница 12: ...s of the entire system when connecting a grounding wire to the output ground terminal both to avoid creating a ground loop referencing problem and also possibly causing a safety issue 4 2 4 Output Ter...

Страница 13: ...ory calibration mode which may result in abnormal operation and change of output accuracy CAUTION The jumper settings can be overridden by the datalogger program if required using special commands Ple...

Страница 14: ...here the potential voltage difference between the datalogger and the SDM CVO4 outputs is considered to be non hazardous less than 50 V then the unit can be used as any other peripheral without undue c...

Страница 15: ...ed to house electrical equipment will usually meet the requirements Campbell Scientific s ENC 12 14 or 16 18 enclosures meet these requirements if fitted with a padlock and with the correct labels on...

Страница 16: ...ed values into input locations using the same principles as given in the manuals for those sensors The measured values would then be scaled using the processing instructions of the datalogger using ei...

Страница 17: ...hat require an isolated and or precise high voltage supply within the current output capability of the SDM CVO4 In this context the SDM CVO4 can be used to provide an isolated supply which can be regu...

Страница 18: ...ces can be controlled by one SDMCVO4 instruction by assigning them consecutive addresses and setting the CVO4Reps parameter to a value equal to the total number of channels of all devices e g to set a...

Страница 19: ...n temperature and relative humidity Each parameter is scaled to 0 to 10000 mVDC and output to a SCADA system through the SDM CVO4 Public WS_ms Public WD_0_360 Public Temp_C Public RH Public WD_0_540 P...

Страница 20: ...S Min Setting 8 68 S Max Setting 2 2 mS SDMSpeed 30 gives 26 04 S SDMSpeed k gives bit_rate INT k 72 625 Resolution When calculating SDMSpeed k the loggers round down to the next higher bit 6 4 Edlog...

Страница 21: ...utput changes in discrete steps e g 2 5 mV in voltage mode When the datalogger works out which of these discrete steps to set for a given scaling value a combination of floating point mathematics foll...

Страница 22: ...eld until the datalogger runs Instruction 103 again to update the output levels required 6 5 Edlog Program Examples The following Edlog program examples are given to help you understand the general pr...

Страница 23: ...rT 5 1 0 Mult Scale to degrees C 6 0 0 Offset Measure solar radiation from an SP Lite 4 Volt SE P1 1 1 Reps 2 32 50 mV 50 Hz Reject Slow Range 3 3 SE Channel 4 4 Loc Radiation 5 100 Mult 6 0 0 Offset...

Страница 24: ...on to cover 0 360 degrees Temperature 25 to 50 degrees C Radiation 0 1000 m 2 s 10 Scaling Array A Loc B P53 1 5 Start Loc ScldOut_1 2 100 A1 WS multiplier 3 5000 B1 WS Offset 4 27 7778 A2 5 5000 B2 6...

Страница 25: ...Array A Loc B P53 1 5 Start Loc ScldOut_1 2 80 A1 WS multiplier 3 3000 B1 WS Offset 4 22 2222 A2 5 3000 B2 6 106 667 A3 7 333 32 B3 8 8 A4 9 3000 B4 Now limit the lowest scaled value to 3000 4 mA As w...

Страница 26: ...made CR10X An example program which show use of the SDM CVO4 as an isolated power supply for 4 sensors requiring 10 V drive and producing 0 100 mV signals This shows how to set the SDM CVO4 into stand...

Страница 27: ...t Diff P2 1 4 Reps 2 04 250 mV Slow Range 3 1 DIFF Channel 4 5 Loc Press_1 5 1 0 Mult 6 0 0 Offset Now turn off the SDM CVO4 by using the command with 0 reps 5 SDM AO4 P103 1 0 Reps 2 00 SDM Address 3...

Страница 28: ...SDM CVO4 4 Channel Current Voltage Output Module 24...

Страница 29: ......

Страница 30: ...ntific Canada Corp CSC 11564 149th Street NW Edmonton Alberta T5M 1W7 CANADA www campbellsci ca dataloggers campbellsci ca Campbell Scientific Centro Caribe S A CSCC 300 N Cementerio Edificio Breller...

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