©2019, GEOKON. All rights reserved.
Document Revision:
E
| Release date: 3/18/19
Model 3810A
Addressable Thermistor String
Instruction Manual
Страница 1: ... 2019 GEOKON All rights reserved Document Revision E Release date 3 18 19 Model 3810A Addressable Thermistor String Instruction Manual ...
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Страница 3: ...ON is not responsible for any damages or losses caused to other equipment whether direct indirect incidental special or consequential which the purchaser may experience as a result of the instal lation or use of the product The buyer s sole remedy for any breach of this agreement by GEOKON or any breach of any warranty by GEOKON shall not exceed the purchase price paid by the purchaser to GEOKON f...
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Страница 5: ...S 3 4 MODBUS CAMPBELL SCIENTIFIC DATALOGGERS 5 4 1 DESCRIPTION 5 4 2 WIRING 5 4 3 SAMPLE CR6 PROGRAM 5 4 4 SAMPLE CR1000 PROGRAM WITH REQUIRED MODEL 8020 38 ADDRESSABLE BUS CONVERTER 6 5 TEMPERATURE CALCULATION 7 5 1 STEINHART HART COEFFICIENTS 7 5 2 FLOATING POINT RESISTANCE READINGS PREFERRED METHOD 7 5 3 RAW ADC ANALOG TO DIGITAL CONVERTER READINGS 7 6 SOFTWARE 8 APPENDIX A SPECIFICATIONS 9 A 1...
Страница 6: ...DEL 3810A ADDRESSABLE THERMISTOR STRING 1 FIGURE 2 MODEL 3810A ADDRESSABLE THERMISTOR 1 FIGURE 3 MODEL 3810A 3 END TERMINATOR 2 FIGURE 4 MODEL 8020 38 ADDRESSABLE BUS CONVERTER 2 FIGURE 5 PC TERMINAL PROGRAM SCREEN CAPTURE 4 ...
Страница 7: ...SUREMENT 3 TABLE 4 EXAMPLE QUERY FLOATING POINT RESISTANCE READING 4 TABLE 5 EXAMPLE RESPONSE FLOATING POINT RESISTANCE READING 4 TABLE 6 DATALOGGERS WITH RS 485 CONVERSION 5 TABLE 7 DATALOGGERS WITHOUT RS 485 CONVERSION 5 TABLE 8 3810A THERMISTOR STRING TO RS 485 TO TTL CONVERTER WIRING 5 ...
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Страница 9: ...ncased in epoxy or glass The beads are small in size and extremely robust with a high degree of stability over a long life span The accuracy and interchangeability of the thermistor bead used on the 3810A is 0 07 C within the temperature range of 0 C to 50 C The cable consists of two twisted pairs each wrapped with aluminized Mylar foil and a single drain wire There are four conductors power groun...
Страница 10: ... function of each of the conductors of the instrument cable TABLE 1 3810A Wiring 2 2 HARDWARE REQUIREMENTS Communications RS 485 half duplex Baud Rate 115200 Power 12 0V 20 1 2mA sensor 2 3 TTL USB TO RS 485 CONVERTER GEOKON manufactures the Model 8020 38 Addressable Bus Converter for connecting addressable strings to personal computers readouts dataloggers and programmable logic controllers The c...
Страница 11: ...check a 16 bit data integrity check calculated over the other byes in the packet 3 3 MODBUS TABLES The most recent sensor reading is stored in a table The reading is presented in different formats in different sections of the table The register location and size of these variables are described in the table below TABLE 2 RAM Storage 3 4 READING 3810A SENSORS While Modbus RTU supports roughly 20 di...
Страница 12: ... program simplicity the 32 bit floating point reading is recommended An example of this query and response is shown in the tables below TABLE 4 Example Query Floating Point Resistance Reading TABLE 5 Example Response Floating Point Resistance Reading FIGURE 5 PC Terminal Program Screen Capture The table above shows the IEEE 754 floating point response as two parts each one is composed of two bytes...
Страница 13: ...h five addressable thermistors The string in this example communicates with the CR6 through the control ports C1 green and C2 white which are set up as ComC1 Constants used in Steinhart Hart equation to calculate sensor temperature for 10k thermistor Define Data Tables DataTable Test 1 1 Sample 5 Celsius IEEE4 Sample Celsius for 5 sensors in string EndTable Campbell Dataloggers with RS 485 3810A S...
Страница 14: ...setup as COM1 Constants used in Steinhart Hart equation to calculate sensor temperature for 10k thermistor Define Data Tables Main Program Const A 1 128706256E 3 Const B 2 342327483E 4 Const C 0 8707279757E 7 Public ErrorCode Result of ModBusMaster communications attempt Public Resistance As Float Resistance of thermistor must be stored as Type Float Public Celsius 5 Calculated Celsius for 5 senso...
Страница 15: ... 3810A Utility program 5 1 STEINHART HART COEFFICIENTS A 1 128706256 10 3 B 2 342327483 10 4 C 0 8707279757 10 7 5 2 FLOATING POINT RESISTANCE READINGS PREFERRED METHOD R Resistance reading from register address 0x0102 5 3 RAW ADC ANALOG TO DIGITAL CONVERTER READINGS Resistance can be found by R ADC reading from register address 0x0100 And temperature is Using an example ADC reading from address 0...
Страница 16: ...gly The three types of strings currently supported are the Addressable Thermistor 3810A String the Addressable VW Vibrating Wire 8020 30 Sensor String and the Addressable MEMS 6150E and 6151E String The ASR contains the following features Communication via Windows COM Ports Selection of all drops individual drops or a combination of drops Recording of data in rows either by button click or cyclic ...
Страница 17: ...using Delrin PVC Length X Diameter 140 x 22 mm 5 5 x 7 8 Working Load 9 07 kg 20 lbs Breaking Strength 22 68 kg 50 lbs Pressure Rating 150 psig 1 MPa Sensors Wire Wireless 248 maximum 30 maximum ADC Resolution 16 bit System Resolution 0 C to 50 C 0 002 C nonlinear largest step System Resolution 20 C to 80 C 0 005 C nonlinear largest step System Repeatability 20 C to 80 C 0 002 C 99 confidence inte...
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Страница 20: ...GEOKON 48 Spencer Street Lebanon New Hampshire 03766 USA Phone 1 603 448 1562 Email info geokon com Website www geokon com GEOKON is an ISO 9001 2015 registered company ...
