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How to demount  System DRST

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Section 3 - Communication Enabler

•  Programming display for system DRST devices
•  Modbus RTU protocol interface over RS485
•  Monitor process value from the built-in display
•  High 2.5 kV isolation to host unit
•  Shielded RJ45 Modbus connector on top

Section 4 - Applications

•   The DRST-CM detachable display adds Modbus RTU RS-485 serial communications to all current and future 

DRST units.

•   The unit converts a wide array of sensors and analog device signals measured by the system DRST, like uni- and 

bipolar mA and voltage signals, potentiometer, Lin. R, RTD and TC, to a Modbus communication line signal.

•   When mounted on a system DRST device any signal coming from or going to I.S. classified area, like AI, AO, DI 

and DO signals, can be converted to a Modbus network.

•   All individual unit operating parameters can easily and quickly be configured by using the Modbus 

communication or by using the front display menu.

•   The easily readable DRST-CM display can be used to read the process signal, simulate the output signal, indicate 

sensor errors and internal module errors.

Section 5 - Technical Characteristics

•   DRST-CM has full DRSL-DISPLAY functionality for unit programming, process signal monitoring and  

diagnostics handling.

•   Modbus RTU protocol is supported using a serial RS-485 communication wiring.
•   Multidrop half-duplex connection via shielded RJ45 connector.
•   High safe galvanic isolation of 2.5 kVAC between the serial wiring and the connected system DRST units.
•   Modbus parameters such as address, baud rate, stop bit(s), and parity bit are configured from the DRST-CM 

display, which also stores parameters.

Section 6 - Mounting / Installation / Programming

•   Mounting in Zone 2 / Div 2.
•   The DRST-CM can be moved from one device to another. The individual system DRST unit configuration of the 

first transmitter can be saved and downloaded to subsequent transmitters.

•   Programmed parameters can be protected by a user-defined password.
•   When mounted on devices that are installed upside down, a menu item allows the display on the DRST-CM to be 

rotated 180o and the up/down buttons to switch function.

Summary of Contents for DRST-CM

Page 1: ...e mail info omega com For latest product manuals www omegamanual info DRST CM Communication Enabler TM Shop online at omega com User sGuide ...

Page 2: ...specifications without notice omega com info omega com Servicing North America U S A Omega Engineering Inc Headquarters Toll Free 1 800 826 6342 USA Canada only Customer Service 1 800 622 2378 USA Canada only Engineering Service 1 800 872 9436 USA Canada only Tel 203 359 1660 Fax 203 359 7700 e mail info omega com For Other Locations Visit omega com worldwide ...

Page 3: ...ection 3 Safety Instructions 6 Section 4 Applications 7 Section 5 Technical Characteristics 7 Section 6 Mounting Installation Programming 8 Section 7 Mounting on a DRST device 8 Section 8 Order 8 Section 9 Electrical Specifications 9 10 Section 10 Modbus Parameter settings 11 12 Section 11 Modbus Settings Routing Diagram 13 14 ...

Page 4: ...ction provided by the equipment may be impaired GENERAL WARNING Until the device is fixed do not connect hazardous voltages to the device The following operations should only be carried out on a disconnected device and under ESD safe conditions General mounting connection and disconnection of Modbus cable Troubleshooting the device HAZARD OUS VOLTAGE Triangle with an exclamation mark Read the manu...

Page 5: ...ltages must be carried out according to the specifications of this manual The technician must use tools and instruments that are safe to use Cleaning When disconnected the device may be cleaned with a cloth moistened with distilled water IECEx ATEX installation in Zone 2 IECEx DEK 13 0026 X Ex nA IIC T5 Gc DEKRA 13ATEX0098 X II 3 G Ex nA IIC T5 Gc For safe installation the following must be observ...

Page 6: ... DRST CM display can be used to read the process signal simulate the output signal indicate sensor errors and internal module errors Section 5 Technical Characteristics DRST CM has full DRSL DISPLAY functionality for unit programming process signal monitoring and diagnostics handling Modbus RTU protocol is supported using a serial RS 485 communication wiring Multidrop half duplex connection via sh...

Page 7: ...e LCD dot display Line 1 can e g show the scaled process value Line 2 can e g show the selected engineering unit Line 3 can e g show the analog output or TAG no Line 4 shows status for communication and e g signal trending RJ45 Modbus Connector Pin 5 RS485 A line Pin 4 RS485 B line Pin 8 RS485 GND and shield Section 8 Order Type Description DRST CM DRSL DISPLAY Communication enabler Configmate int...

Page 8: ... response time 50 Hz 20 ms Signal type RS 485 half duplex Serial protocol Modbus RTU Modbus mode RTU slave Devices on an RS485 line Up to 32 without a repeater Data rates baud 2400 4800 9600 19200 38400 57600 115200 Automatic baudrate detection Yes can be configured ON or OFF Parity Even Odd None Stop bit s 1 or 2 Digital adressing 1 247 Response delay 0 1000 ms Approvals EMC 2004 108 EC EN 61326 ...

Page 9: ...ST DRST DRST DRST CM DRST CM IP54 DRST DRST DRST DRST CM DRST CM DRST CM DRST DISPLAY DRST CM DRST CM DRST CM T T T Modbus RTU Zone 2 Cl 1 Div 2 gr A D Safe Area Modbus RTU Gateway Gateway Modbus RTU Ethernet Modbus TCP IP PLC DCS HMI PC PLC DCS HMI PC Modbus RTU PLC DCS HMI PC Access Point ...

Page 10: ...cepted by all slaves but numbers 1 247 are addresses of specific devices With the exception of broadcast messages a slave device always responds to a Modbus message so the master knows the message was received DRST CM Supported Modbus Function Codes The Function Code defines the command that the slave device is to execute such as read data accept data report status Some function codes have subfunc...

Page 11: ...onse delay 0 1000 ms 0 ms default Modbus slave addressing range 1 247 247 default address Modbus Parameter Storage Saved in non volatile memory in the DRST CM device Factory Default Values are marked in bold Modbus RTU segment line termination A 120 Ohm resistor should be installed on both ends of a RS485 Modbus RTU segment loop to prevent signal echoes from corrupting data on the line DRST CM Mod...

Page 12: ...rticular device Omega A S DRST CM Local Menu xlsx DRST CM local submenu V0R9 Monitor SCROLLING HELPTEXTS 40 0 0000 correct No No xxxx 1 Set correct password OK PASSW OK ADV SET OK XXXX 2 Enter advanced setup menu 10 4mA 1 2 Yes x 3 Enter Language setup o V Enter Password setup v v v Enter Simulation mode 9999 YES Perform Process calibration 0000 NO Enter Display setup Perform Memory operations MEM...

Page 13: ...5 No Returns to Monitor upon succesful Modbus write command OFF STATUS 1 v YES NO STATUS 1 Only if automatic baudrate detection is enabled ORIEN NO ROT DEV OK Monitor 13 The gray shaded menus texts are only shown for guidance and are not part of the DRST CM specific submenu The Modbus submenu is located somewhere in the menu structure of any host device supporting DRST CM The actual place is defin...

Page 14: ...GA if the unit is found to be defective it will be repaired or replaced at no charge OMEGA s WARRANTY does not apply to defects resulting from any action of the purchaser including but not limited to mishandling improper interfacing operation outside of design limits improper repair or unauthorized modification This WARRANTY is VOID if the unit shows evidence of having been tampered with or shows ...

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