Omega Products OMR-6510 Installation Manual
M-3581 for
OMR-6520
OMR-6510
RS-232 to RS-422/RS -485 Converter
RS-422/RS -485 Repeater
User’s Guide
Contents
1. INTRODUCTION............................................................................................1-1
1.1 WHAT IS OMR ?..................................................................................1-1
1.2 OUTSTANDING FEATURES OF OMR.................................................1-1
1.3 OMR-6000 SERIES PRODUCTS OVERVIEW........................................1-3
1.4 EIA RS-485 STANDARD ......................................................................1-3
1.5 RS-485 ON OMR...................................................................................1-4
1.6 OMR RS-485 NETWORK CONFIGURATIONS...................................1-4
1.7 CONSTRUCTING A OMR NETWORK.................................................1-5
1.8 TERMINATION BUS.............................................................................1-6
1.9. SHIELDING............................................................................................1-6
1.10. HOW TO CALCULATE CHECKSUM V ALUE........................................1-7
2. OMR-6520........................................................................................................2-1
2.1. OVERVIEW............................................................................................2-1
2.2. SETUP ....................................................................................................2-6
2.3. INSTALLATION....................................................................................2-7
2.4 PROGRAMMING....................................................................................2-8
3. OMR-6510........................................................................................................3-1
3.1. OVERVIEW............................................................................................3-1
3.2. SETUP ....................................................................................................3-5
3.3 INSTALLATION....................................................................................3-6
3.4 PROGRAMMING....................................................................................3-7
4. INSTALL A BRAND-NEW OMR ................................................................4-1
4.1 INITIALIZE A BRAND-NEW OMR.....................................................4-1
4.2 INSTALL A NEW OMR TO A EXISTING NETWORK........................4-3
5. SOFTWARE UTILITY ....................................................................................5-1
5.1 SOFTWARE INSTALLATION...............................................................5-1
5.2 HOW TO EXECUTE THE OMR ADMINISTRATION........................5-1
5.3 OMR ADMINISTRATION FUNCTION OVERVIEW...........................5-2
6. TROUBLESHOOTING AND MAINTENANCE........................................6-1
Contents i
1. Introduction
1.1 What is OMR ?
OMR is a series of data acquisition modules. It provides a total solution of the data acquisition network and
control system. You can remotely control up to 256 OMR modules on RS-485 network. All you need is to use
a host computer, like a PC (Personal Computer), with one RS-232 serial port for controlling the whole system.
The maximum communication distance is 4000 feet from the host computer.
OMR is based on the RS-485 multi-drop network system, each module has a unique address ID. Using simple
ASCII command & response protocol through standard RS -485 interface can control all the OMR modules in
the RS -485 network.
The OMR modules provide direct linkage to a wide variety of sensors and perform all signal conditioning,
scaling, linearization and conversion. The modules can be used to measure temperature, pressure, flow,
voltage, current and numerous types of digital signals.
1.2 Outstanding Features of OMR
• Industry standard networking
All OMR modules use the RS -485 communication protocol for transmitting and receiving at high rates
and over long distance.
• Two-wire and multi -drop communication
A single twisted pair of wires is used to transmit and receive data between modules. Multi-drop capability
makes system configuration more flexible and easy set -up of a network.
• High transfer speed
OMR modules provide up to 115.2K bps data / command transfer rate. It can promote system bandwidth.
• Simple command / response protocol
All communications are performed with printable ASCII characters. This allows the information to be
processed with string functions common to the most high-level languages.
• Industrial design
The screw terminal plug connectors on every OMR module ensure simple installation and easy
modification. The compact size allows the modules to be mounted on DIN rail, back-panel wall-mount,
etc.
• Watch-dog supervisory
OMR contains a watch-dog supervisory circuitry that will automatically reset the module when the
system fails. In addition, a user-programmable software timer provides a ‘safe’ output signal in the event
of host computer failure.
• High isolation voltage
OMR provides photo -isolators, which ensure high isolation voltage, between the data acquisition circuits
and the communication port. The fatal electric-shock won‘t go through and damage all the modules on
the network.
• Noise immunity
The OMR provide extra noise immunity capability. An electrode, which is coated inside the ABS case,
can reduce electro-magnetic interference (EMI) and noise.
• Harsh environmental protection
Introduction 1-1
A surface coating covers on the PCB and electronic components of the OMR. It allows superior
resistance to harsh environment such as humidity, salt spry and mos t harsh chemicals.
1-2 Introduction
1.3 OMR-6000 series products overview
The OMR-6000 series provides the complete sets of data acquisition modules, including the communication
modules, the analog input modules, the analog output modules, and the digital I/O modules.
Communication Module
• OMR-6510: RS -422/RS-485 Repeater
• OMR-6520: RS -232 to RS-422/RS-485 Converter
• OMR-6530: USB to RS -422/RS-485 Converter
Analog Input Modules
• OMR-6011: Multifunction High Gain Analog Input
Module (with DI/O)
• OMR-6011D: Multifunction High Gain Analog Input with
5 ½ digit LED Display (with DI/O)
• OMR-6012: Analog Input Module (with DI/O)
• OMR-6012D: Analog Input Module with 5 1/2 digit LED Display (with DI/O)
• OMR-6013: 3-channel RTD Input Module
• OMR-6014D: Analog (Transmitter) Input Module with
5 1/2 digit LED Display
• OMR-6017: 8-channel Analog Input Module
• OMR-6018: 8-channel Thermocouple Input Module
Analog Output Modules
• OMR-6021: Single Channel Analog Output Module
• OMR-6024: 4-channel Analog Output Module (with DI)
Digital I/O Modules
• OMR-6050: Module with 7 DI channels and 8 DO channels
• OMR-6052: Isolated Digital Input Module
• OMR-6053: 16-channel digital Input Module
• OMR-6054: 15-channel digital Input Module
• OMR-6056: 15-channel digital Output Module
• OMR-6058: 28-channel programmable digital I/O Module
• OMR-6060: 4-channel Relay Output & Digital Input Module
• OMR-6063: 8-channel Relay Output Module
• OMR-6080: Counter/Frequency Input Module
1.4 EIA RS-485 Standard
The EIA RS-485 interface is a communication standard developed for multi-dropped systems that can
communicate at high rate over long distance. The standard RS-485 can operate at speed up to 10 M bps over
cable length up to 4000 feet.
The RS-485 interface can support up to 32 drivers / receivers on the same line. This allows actual networking
applications on a parity line system (sometimes called multi-drop).
The RS -485 uses differential transmission on a balance line. Its easy wiring makes it popular to use in
industrial applications.
Introduction 1-3
Converter
Converter
Terminator
1.5 RS-485 on OMR
The OMR improves the RS-485 capability for minimizing the user‘s cost. On each OMR module, a half-duplex
RS-485 transceiver is used to communicate with other modules. A single twisted pair of wires, which provides
standard differential transmission, is used to transmit and receive data between modules. The high input
impedance of each OMR receiver allows up to 128 OMR modules on the same RS -485 bus without using a
signal repeater.
The maximum transfer rate of OMR is 115.2Kbps, which is lower than the maximum speed of the RS -485
standard. The slew-rate limiter on every RS -485 transceiver of OMR is very useful for transmitting error-free
data, minimizing EMI, and reducing reflections caused by improperly terminated cables.
The OMR on a network may not use the same power supply. Therefore, the voltage difference between
grounds of the modules may exist.
Excessive output current and power dissipation caused by faults or by bus contention are prevented by the
current limiter and the thermal shutdown circuitry inside the OMR.
1.6 OMR RS-485 Network Configurations
OMR-6000 series is designed under RS-485 multi-drop network architecture. Up to 256 OMR modules can be
controlled in a multi-drop network. The limit of 256 is due to command code. The network can be connected
by simple topology (Figure 1-1) or branch topology (Figure 1-2) or free topology (Figure 1-3).
The OMR -6520 and OMR -6510 are the two basic communication modules to construct a RS-485 network. The
OMR-6520 is a RS-232 to RS-485/RS-422 converter. The OMR -6520 is used to build a RS-485 port for the host
computer by converting standard RS -232 signal into RS-485 signal.
The OMR -6510 is the RS-485 signal repeater, which is used to extend or to lengthen the network distance. An
OMR bus can connect up to 256 modules, each segment is up to 128 modules. Whenever the numbers of the
modules excess 128, the repeater should be used. In addition, the length of a standard RS -485 bus is up to
4000 feet, the repeater should be used whenever the length of a signal bus is more than 4000 feet.
Host
RS-232
OMR Modules
ND-6520
OMR-6520
RS-232/RS-485
RS-232 to RS-485/RS-422
RS-485 bus
Figure 1-1 Simple Topology
1-4 Introduction
Converter
Converter
Repeater
Terminator
Terminat
Terminat
Host
RS-232
OMR-651
0
Host
OMR Modules
OMR I/O modules
OMR Modules
OMR-6510
OMR-6520
RS-232 to RS-485/RS-422
RS-485 bus
RS-485 bus
Figure 1-2 Branch Topology
OMR-6520
RS-232 to RS-485/RS-422
OMR I/O modules
RS-485 bus
Figure 1-3 Free Topology
OMR Modules
OMR-6510
Repeater
1.7 Constructing a OMR Network
Go through the following steps, the user can construct an OMR network easily.
1. Setup an OMR-6520.
2. Connect the host computer with the OMR-6520.
3. Setup one or more OMR-6510 if necessary.
4. Connect the OMR-6510 to extend to RS -485 bus if necessary.
5. Install the OMR utility software from disk.
6. Initialize the brand-new OMR modules.
7. Add the new OMR modules into RS -485 network.
Refer to chapter 2 for executing step 1 and 2. Refer to chapter 3 for executing step 3, 4 and for understanding
the time to install OMR -6510. The knowledge about the software for operating the OMR is in chapter 5. For
executing the step 6 and step 7, refer to chapter 4.
Introduction 1-5
1.8 Termination Bus
In order to avoid signal reflections on the bus, each bus segment has to be blanked off at its physical beginning
and at its end with the characteristic impedance. A termination resister (Rt) is installed for this purpose. The Rt
value - 120Ω ± 2% is recommended, and the detailed connection of Rt can be referred from the “Terminator
Connection” diagram below.
Host
1.9. Shielding
In case of increased interference, a shielded bus cables is recommended to use for wiring between module and
modules. In addition, a shielding also should be done for the cable of power supply and for the signal cables.
Some experiences and recommendations are concerning for shield connection.
1. The shield should be connected with protective earthing at each bus connection.
2. The shield should be applied additionally several times along the course of the cable.
3. The Computer should be applied the shield directly to the appliance or to separate shield rails.
braided shield
Data+
120 ohms
Data-
Terminator Connection
EarthingPoint
Data+
120 ohms
Data-
Isolation
RS-485 Connection
1-6 Introduction
DA
TA
+
DA
TA
-
OMR-Module
Response :
Response :
1.10. How to Calculate Checksum Value
Format of OM R Commands
(LeadingCode)(Addr)(Command)(Data)[Checksum]<CR>
When checksum is enable then [Checksum] is needed, it is
2-character.
[Checksum] = ((LeadingCode)+(Addr)+(Command)+(Data)) MOD 0x100
Example 1: checksum is disable
User Command : $012<CR>
!01400600
Example 2: checksum is enable
User Command : $012B7<CR>
!01400600AC
‘$’ = 0x24 ‘0’ = 0x30 ‘1’ = 0x31 ‘2’ = 0x30
B7 = ( 0x24 + 0x30 + 0x31 + 0x32 ) MOD 0x100
‘!’ = 0x24 ‘0’ = 0x30 ‘1’ = 0x31 ‘4’ = 0x34
‘6’ = 0x36
AC = ( 0x24 + 0x30 + 0x31 + 0x34 + 0x30 + 0x30 + 0x36 + 0x30 + 0x30 ) MOD 0x100
Introduction 1-7
2. OMR-6520
2.1. Overview
What is OMR-6520 ?
OMR-6520 is a RS -232 to RS-422/RS-485 converter, it converts the RS -232 signal to the RS-422/RS-485
signals. The OMR -6520 can be considered as an extension RS-422/RS-485 serial port for the host computer.
A standard 9-pin D-type connector is used to connect the host computer and the OMR-6520. Hence, the
OMR-6520 can connect with all kinds the PC, IPC or Notebook PC, which install a standard RS-232 interface.
Features of OMR-6520
• RS-422/RS-485 transceiver
• Differential 2-wire half-duplex RS -485
• Easily setup and installation
• Auto direction flow control
• Maximum 128 OMR on a bus without using repeaters
• Maximum 256 addressable OMR modules
• High transfer speed
• High isolation voltage
• Lower power consumption
OMR-6520 2-1
Specifications of OMR-6520
² Input
• Interface : standard RS -232 9 pin female D-type connector
• Speed (bps) : 1200(115.2K1), 2400, 4800, 9600, 19.2K,
38.4K, RTS
• Data Format : 9 bits, 10 bits, 11 bits, or 12 bits
² Output
• Interface : RS-485, differential, 2 half-duplex wires
RS-422, differential, 4 full-duplex wires
• Speed (bps) : 1200(115.2K1), 2400, 4800, 9600, 19.2K,
38.4K, RTS
• Max RS -485 network bus distance : 4000 ft. (1200m)
² Isolation
• Isolation voltage : 5000 Vrms(between RS -422/RS-485
network and host computer)
² Bus
• Max loading : 128 OMRs on a RS -485 network
• Max modules : 256 OMRs with one OMR-6510 repeater
² Power
• Power Supply : +10V to +30V
• Power Consumption : 0.95 W
Note 1: 115.2K is supported by version A1.2 or later.
2-2 OMR-6520
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