
Section 8. Operation
527
Term: RTU / PLC
Remote Telemetry Units (RTUs) and Programmable Logic Controllers
(PLCs) were at one time used in exclusive applications. As technology
increases, however, the distinction between RTUs and PLCs becomes more
blurred. A CR6 fits both RTU and PLC definitions.
8.10.3.2 Programming for Modbus
8.10.3.2.1 Declarations (Modbus Programming)
Table
Modbus Registers: CRBasic Port, Flag, and Variable Equivalents
(p. 527)
shows the linkage between terminals configured for control, flags and Boolean
variables and Modbus registers. Modbus does not distinguish between terminals
configured for control, flags, or Boolean variables. By declaring only terminals
configured for control, or flags, or Boolean variables, the declared feature is
addressed by default. A typical CRBasic program for a Modbus application
declares variables and ports, or variables and flags, or variables and Boolean
variables.
Modbus Registers: CRBasic Port, Flag, and Variable
Equivalents
CRBasic Port,
Flag, or Variable
Example CRBasic
Declaration
Equivalent Example
Modbus Register
U
or
C
terminal
configured for control
Public Port(4)
00001 to 00004
Flag
Public Flag(17)
00001 to 00017
Boolean variable
Public ArrayB(56) as
Boolean
00001 to 00056
Variable
Public ArrayV(20)
1
40001 to 40040
1
30001 to 30040
1
1
Because of byte-number differences, each CR6 domain variable translates to
two Modbus domain input / holding registers.
8.10.3.2.2 CRBasic Instructions (Modbus)
Complete descriptions and options of commands are available in
CRBasic Editor
Help
.
ModbusMaster()
Sets up a CR6 as a Modbus master to send or retrieve data from a Modbus slave.
Syntax
ModbusMaster(ResultCode, ComPort, BaudRate, ModbusAddr,
Function, Variable, Start, Length, Tries, TimeOut)
Содержание CR6 Series
Страница 2: ......
Страница 4: ......
Страница 6: ......
Страница 32: ......
Страница 36: ......
Страница 38: ......
Страница 76: ...Section 5 Overview 76 FIGURE 20 Half Bridge Wiring Example Wind Vane Potentiometer ...
Страница 80: ...Section 5 Overview 80 FIGURE 23 Pulse Input Wiring Example Anemometer ...
Страница 136: ......
Страница 251: ...Section 7 Installation 251 FIGURE 46 Running Average Frequency Response FIGURE 47 Running Average Signal Attenuation ...
Страница 454: ...Section 8 Operation 454 FIGURE 104 Narrow Sweep High Noise ...
Страница 459: ...Section 8 Operation 459 FIGURE 106 Vibrating Wire Sensor Calibration Report ...
Страница 535: ...Section 8 Operation 535 8 11 2 Data Display FIGURE 121 CR1000KD Displaying Data ...
Страница 537: ...Section 8 Operation 537 FIGURE 123 CR1000KD Real Time Custom ...
Страница 538: ...Section 8 Operation 538 8 11 2 3 Final Storage Data FIGURE 124 CR1000KD Final Storage Data ...
Страница 539: ...Section 8 Operation 539 8 11 3 Run Stop Program FIGURE 125 CR1000KD Run Stop Program ...
Страница 541: ...Section 8 Operation 541 FIGURE 127 CR1000KD File Edit ...
Страница 542: ...Section 8 Operation 542 8 11 5 PCCard Memory Card Management FIGURE 128 CR1000KD PCCard Memory Card Management ...
Страница 546: ......
Страница 549: ...Section 9 Maintenance Details 549 FIGURE 133 Separate Back Shell from Module FIGURE 134 Disconnect Battery Connector ...
Страница 552: ......
Страница 610: ...Section 11 Glossary 610 FIGURE 137 Relationships of Accuracy Precision and Resolution ...
Страница 612: ......
Страница 648: ......
Страница 650: ......
Страница 688: ......
Страница 689: ......