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SDM-CVO4 4-Channel Current/Voltage Output Module 

; Now update the SDM-CVO4 with the information 
; for the four channels 

 
16:  SDM-AO4 (P103) 
 1:  4 

Reps 

 2:  30 

SDM 

Address 

  3:  5 

Loc [ ScldOut_1 ] 

 

6.5.3  Providing Isolated Power Supplies to Sensors 

This program example sets all the outputs of the SDM-CVO4 to 10 V to 
provide isolated power supplies to four separate sensors. The program includes 
code to put the SDM-CVO4 into standby mode after the measurements are 
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 standby mode. 

 
*Table 1 Program 
  01:   

60 

Execution Interval (seconds) 

 

; Store a fixed value of 5000 = 10 V output 
; in the four scaling locations 

 
1:  Bulk Load (P65) 
 1:  5000 

 2:  5000 

 3:  5000 

 4:  5000 

 5:  0.0 

 6:  0.0 

 7:  0.0 

 8:  0.0 

  9:  1 

Loc [ Scale_1   ] 

 

; Tell the SDM-CVO4 to set all four outputs to 10,000 mV 
; The SDM-CVO4 address is zero in this example. 
; This will cause the SDM-CVO4 to come out of standby 
; mode. 

 
2:  SDM-AO4 (P103) 
 1:  4 

Reps 

 2:  00 

SDM 

Address 

  3:  1 

Loc [ Scale_1   ] 

 

22 

Summary of Contents for SDM-CVO4

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

Page 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...

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

Page 29: ......

Page 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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