Transmitter
From SysCAD Documentation
Navigation: Main Page -> Models -> Process Control Models
Contents |
General Description
The transmitter is used to pass a value to a PID block. Its use is not required but it will add value in better displaying the control logic on a flowsheet.
Diagram
Inputs and Outputs
|
Label |
Input / Output |
No. of Connections |
Description | |
|
|
|
Min |
Max. |
|
|
Tx |
Out |
0 |
1 |
The transmitter value. |
|
RAW |
Out |
0 |
1 |
The transmitter raw value. |
Model Theory
The transmitter can be an orphan model; it need not be connected to any other unit operation. Most of the fields in the transmitter model are for dynamic simulation only in the purpose of control system testing.
The transmitter model can be connected to a PID unit by a control link. To connect, use the insert link function, and select the transmitter as the source and the PID meas(ured value) as the destination. When the connection is made, the transmitter tag will be automatically put into the PID control block.
Data Sections
The default sections and variable names are described in detail in the following tables. The default Transmitter access window consists of one section.
|
Tag / Symbol |
Input / Calc |
Description |
|
On |
Tick Box |
All of the independent Transmitters will be enabled or disabled using this box. |
|
ShowCnv |
Tick Box |
|
|
Tx_Cnt |
Input |
The number of independent Transmitters required. The default is 1. The user may also change this number at any time. However, the unit will always add new transmitters after existing ones, and it will delete them starting from the last transmitter. E.g. if you have 5 transmitters set up and you change this to 4, transmitter number 5 will be deleted. |
|
Check Tags |
Button |
SysCAD will perform a check on the validity of the tag(s). |
|
State |
Output |
The state of the transmitter. If everything is correct and operating normally, the user will see 'OK' in this box. Otherwise the unit will flag an error message, which helps the user to locate the problem with the controller. |
|
Errors: | ||
|
MSG_1 to MSG_2 |
Output |
Any errors will be reported here. These messages are also displayed in the message window. |
|
Each independent Transmitter has the following layout. The first Transmitter will be displayed on the first page. Each page thereafter displays two transmitters. | ||
|
Tag.Cfg.[Transmitter number] | ||
|
ID |
Input |
This will be the same name as the measured tag if not specified. |
|
MeasTag |
Input |
The measured variable, it must be a valid tag name. The user may type the tag in, however it is preferable to use the cut and paste function to avoid any typing errors. |
|
MeasVal |
Output |
The measured variable's value. |
|
Note: The remaining variables are used in Dynamic simulations in conjunctions with control system testing. They have no significance in ProBal thus not documented. | ||
Adding this Model to a Project
Insert into Configuration file
Sort either by DLL or Group.
|
|
DLL: |
Control1.dll |
→ |
Units/Links |
→ |
Control: Transmitter |
|
or |
Group: |
General |
→ |
Units/Links |
→ |
Control: Transmitter |
See Project Configuration for more information on adding models to the configuration file.
Insert into Project
|
|
Insert Unit |
→ |
Control |
→ |
Transmitter |
See Insert Unit for general information on inserting units.
