Omega Products D5121 User Manual

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Basic Unit

 Four Channel Analog Input  Complete Sensor to

RS-485 or RS-232C Interface

 ASCII Format Command/

Response Protocol

 500 V RMS Analog

Input Isolation

 15-Bit Measurement

Resolution

 Continuous Self-Calibration;

No Adjustments of any Kind

 Programmable Digital Filter  Requires 10 V to 30 Vdc

Unregulated Supply

 Transient Suppression on

RS-485 Communications Lines

 Screw Terminal Plug

Connectors Supplied

The D5000 Four Channel Sensor to Computer Modules are a family of complete solutions designed for data acquisition systems based on personal computers and other processor-based equipment with standard serial I/O ports. The modules convert four analog input signals to engineering units and transmit in ASCII format to any host with standard RS-485 or RS-232C ports. These modules can measure temperature, voltage and current. The modules provide direct connection to a wide variety of sensors and perform all signal conditioning, scaling, linearization and conversion to engineering units. The modules contain no pots or

switches to be set. Features such as address, baud rate, parity, echo, etc. are selectable using simple commands over the communications port–without requiring access to the module. The selections are stored in nonvolatile EEPROM which maintains data even after power is removed.

The key to the D5000 series is that the modules are easy to use. You do not need engineering experience in complicated data acquisition hardware. With the D5000 series modules, anyone familiar with a personal computer can construct a data acquisition system.

OMEGABUS

D5000 Series

Four Channel Sensor to Computer Interface Modules

KQSS-14U-12, $30 each, Type K Quick Disconnect Thermocouple

D5321, $275, shown smaller than actual size

KQSS-14U-12, $30 each, Type K Quick Disconnect Thermocouple. Search

omega.com for more information.

250

Basic Unit

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DIGITAL FILTER

The D5000 options include a unique programmable single pole digital filter. The filter is used to smooth analog data in noisy environments. Separate time constants may be specified for small and large signal changes. Typically, a large time constant is specified for small signal changes to filter out noise and provide stable output readings. A smaller time constant may be chosen for large signal changes to provide fast response to such changes.

COMMUNICATIONS

The D5000 are designed to be easy to interface to all popular computers and terminals. All communications to and from the module are performed with printable ASCII characters.

This modular approach to data acquisition is very flexible, easy to use and cost effective. The modules can be mixed and matched to fit your application. They can be placed remote from the host and from each other. You can string up to 30 modules on one set of wires by using RS-485 with repeaters.

The D5000 Series is completely hardware and software compatible with the D1000, D2000, D3000 and D4000 series and may be mixed in any combination.

All modules are supplied with screw-terminal plug connectors and captive mounting hardware. The connectors allow system expansion, reconfiguration or repair without disturbing field wiring.

THEORY OF OPERATION

D5000 modules are complete four-channel data acquisition systems. Each unit contains analog signal conditioning circuits optimized for a specific input type. The amplified sensor signals are converted to digital data with a microprocessor-controlled integrating A/D converter. Offset and gain errors in the analog circuitry are continuously monitored and corrected using microprocessor techniques. The D5000 converts the digital signal data into engineering units using look-up tables. The resultant data is stored in ASCII format in a memory buffer. The modules continuously convert data at the rate of 8 conversions per second and store the latest result in the buffer.

The host computer may request data by sending simple ASCII commands to the module.

The D5000 will instantly respond by communicating the ASCII buffer data back to the host.

USER OPTIONS

The D5000 offers a variety of userselectable options including choice of address, baud rate, parity, echo, etc. All options are selectable using simple commands over the communications port. All options are stored in a nonvolatile EEPROM which maintains data even after power is removed.

This allows the information to be processed with string functions common to most high-level anguages such as BASIC. For computers that support standard ports such as RS-232C, no special machine language software drivers are necessary for operation.

RS-232C is not designed to be used as a multiparty system; however, the module can be daisy-chained to allow many modules to be connected to a single communications port.

In this network, any characters transmitted by the host are received by each module in the chain and passed on to the next module until the information is echoed back to the host. If a module is correctly addressed and receives a valid command, it transmits a response on the daisy chain network. The response will be rippled through any other modules in the chain until it reaches the host.

RS-485 was developed for multidropped systems that can communicate at high data rates over long distances. For systems requiring many modules, high speed or long distances, RS-485 is recommended.

D1321, $325, shown smaller than actual size

A1000, $250, RS-232 to RS-485 converter/repeater

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COMMAND SET

The D5000 Series uses a simple command/response protocol for communication. A module must be interrogated by the host to obtain data. A module can never initiate a command sequence. A typical command/ response sequence could look like this:

Command:

$1RD

Response:

*+00075.00

A command is initiated with a command prompt, which may be a dollar sign ($) or a pound sign (#). Following the prompt, a single address character must be transmitted. Each module on a communications bus must be set up with a unique address. The command is directed in this case to module address ‘1’. The address is followed by a two-character command, which in this case is RD for Read Data. The command is terminated with a carriage return. The table below shows the D5000 commands.

For each case, a sample command and response is shown. Notice that some commands only respond with an * acknowledgment.

UTILITY SOFTWARE

The utility software CD contains executable programs that make the D5000 series easier to learn and use. The executable programs can be run on IBM PC/XT/AT or compatible computers. A menudriven setup program is provided to simplify configuration of all userselectable options such as address, baud rate and parity. Contextsensitive help is available during configuration for each selectable parameter.

The utility software also contains programming examples written in high level languages such as Visual Basic and C. The examples are easily configured for COM1: or COM:2: ports are provided in ASCII text format. One copy of the utility software CD is inclued with each D5000 module.

D5000 Scaling

Each D5000 can output data in easyto-understand engineering units that may be instantly read and interpreted, without software conversion, by a host computer. Using simple ASCII commands, the voltage or current input range of a D5000 module can be rescaled to represent desired engineering units such as degrees

or psi.

For example, an application requires the displayed output values from a D5251 4-20 mA current input module to be rescaled to 0 to 100%. The D5251 module has an actual input range of 0-25 mA to make it easier to adjust for zero and span and to allow for drift in the end points of the input.

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Write Protected Commands

For greater data security, options are available to echo transmitted commands and to send and receive checksums.

Typical Typical

Command Definition Command Response

CZ Clear Zero $1CZ * ID IDentification $1IDBOILER * RR Remote Reset $1RR * SU Setup Module $1SU31070142 * TS Trim Span $1TS+00600.00 * TZ Trim Zero $1TZ+00000.00 * WEA Write Extended Address $1WEA3031 * WMN Write MiN Displayed Value $1WMN+00000.00 * WMX Write MaX Displayed Value $1WMX+00025.00 *

4-20 mA

D5251

4-20 mA/

RS-232

4-20 mA

Transmitter

Scaling to desired engineering units.

D5000 Series Command Set

Typical Typical

Command Definition Command Response

RB Read Block of Data $1RB *+00070.00

*+00112.00 *+00555.00

RD Read Data $1RD *+00072.00 REA Read Extended Address $1REA *3031 RID Read IDentification $1RID *BOILER RMN Read Displayed MiNimum $1RMN *+00025.00 RS Read Setup $1RS *31070142 RSU Read Setup $1RSU *31070142 RZ Read Zero $1RZ *+00000.00 WE Write Enable $1WE *

Dimensions shown in mm (in.)

Side view

Front view

D5000 Mechanicals and Dimensions Case: ABS with captive hardware Connector: Screw terminal barrier

plug (supplied)

NOTE: Spacing for mounting screws = 2.700" (6.858 cm). Screw threads are 6 X 32

D5000 dimensional drawing

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COMMON SPECIFICATIONS

ANALOG Channels: Four analog input Maximum CMV:

Input to output at 60 Hz: 500 V rms Leakage: Input to output at 115 V rms, 60 Hz: <2µA rms

Resolution: 15-bit measurement Conversion Speed:

8 conversions per second

Common Mode Rejection:

100 dB at 50/60 Hz Calibration: Autozero, no adjustment pots

DIGITAL Microcomputer: 8-bit CMOS Filtering: Small and large signal

digital filtering with user selectable time constants

COMMUNICATIONS Baud Rates:

300, 600, 1200, 2400, 4800, 9600, 19,200, 38,400, 57,600, 11,5200 Data Format: NRZ asynchronous; 1 start bit, 7 data bits, 1 parity bit and 1 stop bit

Parity: Odd, even, none Address: User selectable address Protocol: ASCII format Multidrop Modules:

Up to 30 per host serial port

Communications: Distance up to 1219 m (4000') (RS-485)

Transient Suppression:

On RS-485 communication lines

Communications Error:

Checking via checksum

Communications Setups:

Stored in EEPROM

POWER REQUIREMENTS Unregulated: 10 V to 30 Vdc,

0.75W max. Protected against power supply reversals.

ENVIRONMENTAL Temperature Range: Operating: -25 to 70°C Storage: -25 to 85°C Relative Humidity:

0 to 95% non-condensing

D5100 VOLTAGE INPUTS Input Ranges: ±100 mV, ±1 V,

±5 V, ±10 V, ±100 Vdc

Resolution: 0.01% of FS (4 digits) Accuracy: ±0.02% of FS max Zero Drift: ±1 count max (autozero) Span Tempco: ±50ppm/°C max Input Burnout Protection:

To 250 Vac

Input Impedance:

≤ +1 V input = 100 MΩ min ≥ +5 V input = 1 MΩ min

D5200 CURRENT INPUT Current: 4-20 mAdc

Resolution: 0.04% of FS Accuracy: 0.04% of FS Zero Drift: ±1 count max

(autozero)

Span Tempco: ±50ppm/°C max Voltage Drop: ±1.0V max D5300 THERMOCOUPLE INPUTS Thermocouple Types:

J, K, T, E (factory set)

Ranges: J = -200 to 760°C K = -150 to 1250°C T = -200 to 400°C E = -100 to 1000°C Resolution: ±1° Overall Accuracy (Error from all sources) from 0 to 40°C Ambient:

±1.0°C Typical

Input Impedance: 100 MΩ min Lead Resistance Effect:

<20µV per 350Ω Open thermocouple and overrange indication

Input Burnout: Protection to 250 Vac User Selectable: °C or °F D5450 THERMISTOR INPUTS Thermistor Types: 2252Ω at 25°C Range: 0 to 100°C Resolution: 0.01°C or °F Accuracy: ± 0.1°C Input Protection: to 30 Vdc User Selectable: °C or °F

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Each unit is supplied with a CD ROM that includes a complete operator’s manual and Windows setup software. Ordering Example: D5111 four channel 100 mV input module with RS-232C output and OMEGACARESM1 year extended warranty for D5111

(adds 1 year to standard 1 year warranty),

$250 + 25 =

$275.

Model Number Price Description

A1000 $250 RS-232 to RS-485 converter, 115 Vac power A1000-230 250 RS-232 to RS-485 converter, 230 Vac power A1000-CABLE 15 1.5 m (5') cable, male to female A2000 200 RS-232 to RS-485 converter, 10 to 30 Vdc power D1000-C9 20 1.8 m (6') RS-232 cable for D5000, (DB9F connector one end, other end stripped)

Each unit supplied with operator’s manual. 5000 Series modules are also available with Modbus RTU protocol. To order modules with Modbus RTU protocol, add suffix “M” at the end of the model number, no additional charge.

Ordering Example: A1000 RS-232 to RS-485 converter, 115 Vac power, and OMEGACARESM1 year extended warranty for A1000 (adds 1 year to standard 1 year warranty),

$250 + 25 =

$275.

Omega Products D5121 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual