Related Manuals for Campbell 4-Channel Current/Voltage SDM-CVO4
Summary of Contents for Campbell 4-Channel Current/Voltage SDM-CVO4
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Page 1: User Guide
SDM-CVO4 4-Channel Current/Voltage Output Module User Guide Issued: 13.3.08 © Copyright 2001-2007 Campbell Scientific Inc. Printed under Licence by Campbell Scientific Ltd. CSL 436... - Page 3 Guarantee This equipment is guaranteed against defects in materials and workmanship. This guarantee applies for twelve months from date of delivery. We will repair or replace products which prove to be defective during the guarantee period provided they are returned to us prepaid. The guarantee will not apply to: Equipment which has been modified or altered in any way without the written permission of Campbell Scientific...
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Page 5: Table Of Contents
Contents 1. Introduction... 1 2. Specifications ... 2 3. Power Considerations... 4 4. Installation... 4 5. General Principles of Use ... 12 6. Datalogger Instruction (103)... 13 Figures 2.1 General Specifications ...2 2.2 Output Specifications...3 2.3 Isolation Specifications...3 4.1 Connection to a Datalogger ...4 4.2 Output Device Connections...6 4.2.1 Voltage Output Mode ...6 4.2.2 Current Output Mode...6... - Page 6 Contents Tables 4-1. Datalogger to SDM-CVO4 Connections...4 4-2. Switch Position and Addresses ...10 6-1. Description of Instruction 103 ...14...
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Page 7: Introduction
SDM-CVO4 4-Channel Current/Voltage Output Module The SDM-CVO4 is a synchronously addressed datalogger peripheral designed to allow the datalogger to output variable voltage or current signals under program control. Figure 1. SDM-CVO4 (shown without mounting brackets) 1. Introduction The SDM-CVO4 expands the analogue output capability of Campbell Scientific dataloggers. -
Page 8: Specifications
SDM-CVO4 4-Channel Current/Voltage Output Module The SDM-CVO4 is a synchronously addressed datalogger peripheral. Datalogger control ports 1, 2 and 3 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 in successive input locations in the datalogger. -
Page 9: Output Specifications
2.2 Output Specifications Voltage Mode: Current Mode: 2.3 Isolation Specifications Design criteria: Tested isolation: Maximum recommended continuous operating voltage: Instruction Manual Range: 0 – 10,000 mV Resolution: 2.5 mV Maximum Output Current: 30 mA per channel. Minimum load current: 5 μA if output < 200 mV. Accuracy (+23°C) ±0.02% of set voltage, + (±... -
Page 10: Power Considerations
SDM-CVO4 4-Channel Current/Voltage Output Module 3. Power Considerations The SDM-CVO4 power requirements are large compared to most Campbell Scientific products, especially when driving significant loads. Care must be taken to ensure that the power supply can cope with this higher demand. Alkaline batteries are not recommended for long term applications. -
Page 11: Use Of The Spring-Loaded Terminal Blocks (Top Position)
Instruction Manual insert a small screwdriver into either the top or front slot, as appropriate, and push to open the terminal spring. Strip any insulation from the wire to give 7 to 9 mm bare wire. Push the wire into the opening, and, while holding it in position, withdraw the screwdriver to release the spring. -
Page 12: Output Device Connections
SDM-CVO4 4-Channel Current/Voltage Output Module 4.2 Output Device Connections For each output channel there are four terminals which are labelled V there are two ground ( are internally connected; two are provided for convenience. 4.2.1 Voltage Output Mode The V is set to operate in voltage mode or an unregulated 15 VDC power source in current mode. - Page 13 a) The remote device powers the loop, where, depending on the ground referencing requirements of that device, the connection can be as shown in the diagrams below: CVO4 CVO4 b) The SDM-CVO4 provides the voltage source to drive the loop. In this case the only real option is: CVO4 In both cases you need to consider whether the voltage supply is high enough to...
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Page 14: Shield And Ground Connections
SDM-CVO4 4-Channel Current/Voltage Output Module 4.2.3 Shield and Ground Connections It is generally advisable to used shielded (screened) cable when connecting the output to any remote system to reduce the chances of noise pickup. The shield will only be effective if it is connected to a good ground reference point. As a result of the isolation barrier in the SDM-CVO4, the ground terminals associated with the output connector of each channel cannot be considered as good ground reference points. -
Page 15: Sdm Address Setting
Select channel(s) by fitting jumper (s) between appropriate terminals. (Current mode only.) Jumper shown fitted to ‘enable’ Channel 4. Jumper shown fitted in the unconnected ‘stored’ position. CAUTION Do not store the jumpers between any other pins in the block as this may switch the module into a factory calibration mode, which may result in abnormal operation and change of output accuracy. -
Page 16: Safety Considerations
SDM-CVO4 4-Channel Current/Voltage Output Module The address switch has a hexadecimal setting position (0..F). Most datalogger instructions require you to enter the address as a base 4 number. Please see your datalogger manual for more details of the convention required. 4.5 Safety Considerations Where the potential voltage difference between the datalogger and the SDM-CVO4 outputs is considered to be non-hazardous (less than 50 V) then the... - Page 17 Where the SDM-CVO4 is going to be used in applications where the potential difference between the datalogger and the output terminals exceeds 50 V RMS AC, 74 VDC then careful consideration has to be taken to ensure safe operation and compliance with local safety regulations. For such applications Campbell Scientific does not supply the device as a stand-alone device which will meet all safety requirements.
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Page 18: General Principles Of Use
SDM-CVO4 4-Channel Current/Voltage Output Module If you have any doubts about the safety of your installation please first seek advice from your local safety advisor and then Campbell Scientific if you require further technical details. CAUTION To ensure safe and correct operation, the SDM-CVO4 must be installed where there is no risk of water ingress or condensation. -
Page 19: Datalogger Instruction (103)
Instruction Manual compensated for. With the SDM-CVO4 as an excitation source, any drift in its output accuracy, or of the logger measurement accuracy, can result in a combination of those errors. It is worth investigating, therefore, the exact requirements of the sensors you wish to use. For instance, on closer inspection of the specification of many pressure sensors you will often find the recommendation of 10V excitation, but in reality many will accept a lower voltage. -
Page 20: Description Of Instruction 103
SDM-CVO4 4-Channel Current/Voltage Output Module range of -20°C to +50°C would be scaled so at -20C the output is 0 mV and at +50°C the output is 10000 mV. To do this with the SDM-CVO4 you would use the mathematical functions of the datalogger to calculate a scaled value in a new input location, so that the value is -5000 when the temperature is -20°C and +5000 at +50°C. -
Page 21: Edlog Program Examples
If the SDM-CVO4 loses power for any reason, when power is restored the outputs will return to the default ‘off’ state. This will be held until the datalogger runs Instruction 103 again to update the output levels required. 6.2 Edlog Program Examples The following program examples are given to help you understand the general principles involved in the use of the SDM-CVO4. - Page 22 SDM-CVO4 4-Channel Current/Voltage Output Module 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 ; Now output data in the normal way to final storage 5: If time is (P92) 1: 0 Minutes (Seconds --) into a...
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Page 23: Restricted Range Current Output Modes (4-20 Ma)
7: -1666.67 B3 8: 10 9: -5000 ; Now update the SDM-CVO4 with the information ; for the four channels 11: SDM-AO4 (P103) 1: 4 Reps 2: 30 SDM Address 3: 5 Loc [ ScldOut_1 ] 6.2.2 Restricted Range Current Output Modes (4-20 mA) When driving a system that requires a restricted current range then the full-scale range is reduced accordingly. -
Page 24: Providing Isolated Power Supplies To Sensor
SDM-CVO4 4-Channel Current/Voltage Output Module ; then set the value to –3000 13: Z=F (P30) 1: -3000 2: 00 3: 5 14: End (P95) 15: End (P95) ; Now update the SDM-CVO4 with the information ; for the four channels 16: SDM-AO4 (P103) 1: 4 Reps... - Page 25 ; Wait 100 m s for it to power-on an d the outputs to stabilize ; You ma y need to increase this dela y if the sensors ; themselves ; have a power-on delay 3: Excitation with Delay (P22) 1: 1 Ex Channel 2: 0000...
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Page 26: Crbasic Sdmcvo4 Instruction
SDM-CVO4 4-Channel Current/Voltage Output Module 6.3 CRBasic SDMCVO4 Instruction This instruction is used to control the SDM-CVO4 four channel current/voltage output device. Syntax SDMCVO4 ( CVO4Source, CVO4Reps, SDMAddress, CVO4Mode ) Remarks This instruction controls the SDM-CVO4, which outputs a voltage or a current. Internal jumpers are used to set the mode for the device, but the jumpers can be overridden with the Mode parameter in this instruction. -
Page 27: Sdm-Cvo4 Instruction Example
6.4 SDM-CVO4 Instruction Example This program example is for a weather station measuring wind speed, wind direction, 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... - Page 28 SDM-CVO4 4-Channel Current/Voltage Output Module EndIf ' Scale the measurements for the SDM-CVO4 to output 0-10000 mV WSOut = WS_ms*200 'WS: 0-50 m/s = 0-10000 mV WDOut = WD_0_540 *18.59 'WD: 0-540 deg = 0-10000mV TempOut= 100*(Temp_C+40) 'Temp: -40-60 deg C = 0-10000 mV RHOut = RH *100 'RH: 0-100 % RH = 0-10000 mV ' Send mV outputs to SDM-CVO4 using the option to override the switch settings SDMCVO4 (CVO4Output(),4,0,10)
- Page 30 Please visit www.campbellsci.com to obtain contact information for your local US or International representative. Campbell Scientific Companies Campbell Scientific, Inc. (CSI) 815 West 1800 North Logan, Utah 84321 UNITED STATES www.campbellsci.com info@campbellsci.com Campbell Scientific Africa Pty. Ltd. (CSAf) PO Box 2450 Somerset West 7129 SOUTH AFRICA www.csafrica.co.za...