Answer:
Create a FB block for getting this advantage
In Data type Address Initial Value Comment
Drive Run Bool 0.0 False OFF1
Flt ACK Bool 0.1 False Fault Reset
F_Jog Bool 0.2 False
R_Jog Bool 0.3 False
Main_N_Set Int 2.0 0 Speed Set Point
Pos_Torque Int 4.0 0 Positive torque Limit
Neg_Torque Int 6.0 0 Negative Torque Limit
IO_address Int 8.0 0 Device Address
Out Data type Address Initial Value Comment
RTS Bool 10.0 False Ready to Start
Rdy_op Bool 10.1 False Ready to Operation
IOP Bool 10.2 False In Operation
Fault Bool 10.3 False Fault Presen
Jogging Bool 10.4 False Jogging With Jog Speed
Mtr_Speed Int 12.0 0 Speed of mtr in RPM
Mtr_Torq Int 14.0 0 Mtr torque
Mtr_I Int 16.0 0 Mtr Current
Mtr_Kw Int 18.0 0 Mtr Kw
CommErr Int 20.0 0 Comm Err
State Data type Address Initial Value Comment
Control word
B08_Inch0 Bool 22.0 False .....
B09_Inch1 Bool 22.1 False ......
B10_Plc_Contl Bool 22.2 True ......
B11_F_Enable Bool 22.3 True Jog Forwad
B12_R_Enable Bool 22.4 True Jog Reverse
B13_Mop_Up Bool 22.5 False ...........
B14_Mop_Dn Bool 22.6 False ....
B15_Ex_Flt Bool 22.7 Fase ..........
B00_On Bool 23.0 False OFF1
B01_NO_Coast Bool 23.1 True OFF2
B02_NO_Qstop Bool 23.2 True OFF3
B03_Enable Bool 23.3 True
B04_RFG_Enable Bool 23.4 True
B05_RFG_SRT Bool 23.5 True ...........
B06_SP_Enable Bool 23.6 True ....
B07_Flt_ACK Bool 23.7 False Fault Reset
W_2 Int 24.0 0 spare
Speed_Set Int 26.0 0 Main N Set
Torq_Pos Int 28.0 0 Torque positive
Torq_Neg Int 30.0 0 Torque Negative
STATUS WORD
Out0 Byte 32.0 B#16#0 spare
B00_RTS Bool 33.0 False Ready to Start
B01_Rdy_op Bool 33.1 False Ready to Operation
B02_IOP Bool 33.2 False In Operation
B03_Fault Bool 33.3 False Fault Present
B04_OFF2 Bool 33.4 False Coast
B05_OFF3 Bool 33.5 False Q_Stop
B06_Inhibit Bool 33.6 False .......
B07_Warning Bool 33.7 False ..............
W2 Int 34.0 0 Spare
W3_Mtr_Speed Int 36.0 0 Speed of mtr in RPM
W4_Mtr_Torq Int 38.0 0 Mtr torque
W5_Mtr_I Int 40.0 0 Mtr Current
W6_Mtr_Kw Int 42.0 0 Mtr Kw
CommErr Int 44.0 0 Comm Err
TEMP Data type Address Initial Value
Address_W WORD 0.0
Ret_Val0 Int 2.0
Ret_Val1 Int 4.0
Block: FB100
Network: 1
L #IO_adss
T #Adress_W
NOP 0
Network: 2
A #Drive Run
= #B00_ON
A #Flt ACK
= #B07_Flt_ACK
A #F_JoG
= #B011_F_Jog
A #R_Jog
= #B12_R_Jog
Network: 03
L # Main _N_Set
T #Speed Set
L #Pos_Torque
T #Torq_pos
L #Neg_Torque
T # Torq_Neg
L #IO_Address
T # Address_W
Network: 04 (DATA SEND TO DRIVE)
Call "DPWR_DAT" SFC15
LADDR :=Adress_w
RECORD :=P#DB100.DBX22.0 BYTE 10
RET_VAL :=Ret_Val0
Network: 05
L #Ret_Val0
T # CommErr
NOP 0
Network: 06(DATA RECEIVE FROM DRIVE)
Call "DPRD_DAT" SFC14
LADDR :=Adress_w
RECORD :=P#DB100.DBX32.0 BYTE 14
RET_VAL :=Ret_Val1
Network: 07
L #Ret_Val1
T # CommErr
NOP 0
Network: 08
A #B00_RTS
= #RTS
A #B01_Rdy_OP
= #Rdy_op
A #B02_IOP
= #IOP
A #B03_Fault
= #Fault
Network: 09
L #W3_Mtr_Speed
T #Mtr_Speed
L #W4_Mtr_Torq
T #Mtr_Torq
L # W5_Mtr_I
T #Mtr_I
L #W6_Mtr_Kw
T #Mtr_Kw
NOTE: Create DB100 block as Instant data block of FB100
CONTROL/Status word can be changed by your setting in STARTER/SCOUT
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Showing posts with label PLC. Show all posts
Showing posts with label PLC. Show all posts
Sunday, August 19, 2012
Thursday, June 28, 2012
Status word description
The status word can be seen by displaying the STATUS column while monitoring in STL view. The RLO (bit 1) and the STA (bit 2) are also displayed in the RLO and STA column.
BR Binary Result Bit (Status Word, Bit 8)
The BR bit is bit 8 of the status word.
The BR bit transfers the results obtained from processing Statement List (STL) instructions on to the next instructions to be processed.
The Binary Result transfers the result of the operations
onto the next instruction for reference. When the BR bit is 1 it enables the outputof the block (ENO) to be TRUE and thus allow other blocks after it to be
processed. The SAVE, JCB and JNB instructions set the BR bit.
· If an error occurred during execution, the BR bit is ‘’0”.
· If the function was executed with no error, the BR bit is ‘’1”.
CC 1, CC 0 Condition Codes (Status Word, Bits 6 and 7)
The Condition Code bits provide results for comparison and math instructions.
Comparison Instructions
CC 1
|
CC 0
|
Meaning
|
0
|
0
|
ACCU 2 = ACCU 1
|
0
|
1
|
ACCU 2 < ACCU 1
|
1
|
0
|
ACCU 2 > ACCU 1
|
1
|
1
|
Unordered (floating point comparison only)
|
Math Instructions, without Overflow
CC 1
|
CC 0
|
Meaning
|
0
|
0
|
Result = 0
|
0
|
1
|
Result < 0
|
1
|
0
|
Result > 0
|
Integer Math Instructions, with Overflow
CC 1
|
CC 0
|
Meaning
|
0
|
0
|
Negative range overflow in ADD_I and ADD_DI
|
0
|
1
|
Negative range overflow in MUL_I and MUL_DI
|
1
|
0
|
Negative range overflow in ADD_I, ADD_DI, SUB_I, and SUB_DI
|
1
|
1
|
Division by 0 in DIV_I, DIV_DI, and MOD_DI
|
Floating Point Math Instructions, with Overflow
CC 1
|
CC 0
|
Meaning
|
0
|
0
|
Gradual underflow
|
0
|
1
|
Negative range overflow
|
1
|
0
|
Positive range overflow
|
1
|
1
|
Not a valid floating-point number
|
Shift and Rotate Instructions
CC 1
|
CC 0
|
Meaning
|
0
|
0
|
Bit shifted out = 0
|
1
|
0
|
Bit shifted out = 1
|
Word Logic Instructions
CC 1
|
CC 0
|
Meaning
|
0
|
0
|
Result = 0
|
1
|
0
|
Result <> 0
|
OV Overflow (Status Word, Bit 5)
The OV bit displays errors for math instructions or comparison instructions with floating point numbers.
The OV bit is bit 5 of the status word.
It is set by a math instruction with floating point numbers after a fault has occurred (overflow, illegal operation, comparison unordered). The OV bit is reset when the fault is eliminated.
The OS bit stores the OV bit if an error occurs during math instructions or comparison instructions with floating point numbers.
The OS bit is bit 4 of the status word.
The OS bit is set, together with the OV (Overflow) bit, in the event of a fault. It remains set after the fault has been eliminated. It thus stores the OV bit status and indicates whether or not a fault has occurred in one of the previously executed instructions.
The following commands reset the OS bit:
· JOS (Jump if OS=1)
· Block call instructions
· Block end instructions
OR (Status Word, Bit 3)
The OR bit is used for combining AND functions before OR functions.
The OR bit is status word bit 3.
The OR bit is set if the RLO of the AND logic operation is 1. This anticipates the result of the OR logic operation. Every other bit-processing instruction resets the OR bit.
STA Status Bit (Status Word, Bit 2)
The STA bit stores the value of an addressed bit.
The STA bit is bit 2 of the status word.
The status of a bit logic instruction that performs a read access to memory (A, AN, O, ON, X, or XN) is always the same as the value of the addressed bit. The status of a logic instruction that may perform a write access to the memory (R, S, or =) is the same as the value of the written bit or, if writing is not performed, the same as the value of the addressed bit. The status bit has no significance for bit instructions that do not access the memory. These instructions set STA to 1. The status bit is not read by instructions, it is interpreted for you when viewing the online status of program variables.
RLO Result of Logic Operation (Status Word, Bit 1)
The RLO bit stores the result of a logic operation string or comparison instruction.
The RLO bit is status word bit 1.
The first instruction in a segment checks the contact signal state. The RLO is set to ‘’1’’ if the check is executed. The second instruction also checks the contact signal state. This check result is now combined with the value stored in the RLO bit according to the Boolean algebra rules and stored in the RLO bit. This logic string ends after an assignment or a conditional jump. Depending on the RLO bit value, an assignment or a conditional jump is executed.
/FC First Check Bit (Status Word, Bit 0)
The /FC bit signal state controls a logic operation string.
The /FC bit is status word bit 0.
Each logic operation queries the /FC bit signal state and the addressed contact.
· If the /FC bit signal state equals ‘’1,’’ an instruction logically combines the result of its signal state check on its addressed contact with the RLO generated since the first check and stores the result in the RLO bit.
· If the /FC bit signal state equals ‘’0,’’ the logic string begins with a first check.
The logic string ends and the /FC bit is set to ‘’0’’ with the assignment of a value (S,R,=) or with a RLO-dependent jump instruction.
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Statu Word
Status word bits are read and written by the CPU and directly by your program statements.
As each of your instructions is processed, CPU status word bits are used according to the function of each instruction. Status word bits are used to link your instructions together and to provide immediate results and error information. Your program statements can then read status word bits and take action, if necessary.
Status Word
BR CC 1 CC 0 OV OS OR STA RLO /FC
Notation for an instruction’s effect upon the status word:
- No read or write
* Read
x May write "1" or "0"
0 Reset to "0"
1 Set to "1"
See also:
CPU Resister !--RELATED-POSTS-STARTS-->
Types of PLC Programing Language
PLC user program is under the control system designer process control requirements, through the establishment of PLC programming language design. Developed by the International Electrotechnical Commission standard industrial control programming language (IE PLC user program is under the control system designer process control requirements, through the establishment of PLC programming language design.
The five languages in the IEC Standard 61131-3 are:
Instruction List (IL): A low-level language very similar to assembly language. The code is compact and suitable for small projects. It not very powerful. The other languages are easier to use and document. It has been years since I have used it and do not miss it.
Structured Text (ST): A high level language structured like Pascal. Users trained in high level text languages would be comfortable with ST.
Ladder Diagrams (LD): Also commonly known as Ladder Logic. Modeled after the electrical wiring of contacts and relays used to create logic. It made the transition from Relay logic (using actually electrical relays) to the PLC easier. It falls short when tasks become complex. Not the best for modular PLC programming. This language will look very familiar to Electricians.
Function Block Diagram (FBD): The blocks contain procedures or functions to act on the input "wires" and output the result. It lends itself readily to standardizing, modulating, and maintaining programs. I prefer this over LD, and many are coming to realize its advantages. Ladder Diagrams will die a slow death.
Sequential Function Chart (SFC): This graphic language is great for concurrent parallel sequential operations. It is self documenting. It very useful pulling together in a flow chart form the other PLC programming elements such as function blocks (FB) or structured text (ST). Its format shows overall program flow very well making it faster and easier to understand what the program is doing. Easy to identify the section of interest for troubleshooting and program improvement.
By the way...a common belief is that you would be able to quickly convert between the above languages. This is false. Although they have common elements they also have differences that preclude the possibility.
Ref:http://www.plcedge.com !--RELATED-POSTS-STARTS-->
The five languages in the IEC Standard 61131-3 are:
Instruction List (IL): A low-level language very similar to assembly language. The code is compact and suitable for small projects. It not very powerful. The other languages are easier to use and document. It has been years since I have used it and do not miss it.
Structured Text (ST): A high level language structured like Pascal. Users trained in high level text languages would be comfortable with ST.
Ladder Diagrams (LD): Also commonly known as Ladder Logic. Modeled after the electrical wiring of contacts and relays used to create logic. It made the transition from Relay logic (using actually electrical relays) to the PLC easier. It falls short when tasks become complex. Not the best for modular PLC programming. This language will look very familiar to Electricians.
Function Block Diagram (FBD): The blocks contain procedures or functions to act on the input "wires" and output the result. It lends itself readily to standardizing, modulating, and maintaining programs. I prefer this over LD, and many are coming to realize its advantages. Ladder Diagrams will die a slow death.
Sequential Function Chart (SFC): This graphic language is great for concurrent parallel sequential operations. It is self documenting. It very useful pulling together in a flow chart form the other PLC programming elements such as function blocks (FB) or structured text (ST). Its format shows overall program flow very well making it faster and easier to understand what the program is doing. Easy to identify the section of interest for troubleshooting and program improvement.
By the way...a common belief is that you would be able to quickly convert between the above languages. This is false. Although they have common elements they also have differences that preclude the possibility.
Ref:http://www.plcedge.com !--RELATED-POSTS-STARTS-->
Monday, June 25, 2012
What is PLC & how it work
PLCs are often defined as miniature industrial computers that contain hardware and software that is used to perform control functions. A PLC consists of two basic sections: the central processing unit (CPU) and the input/output interface system. The CPU, which controls all PLC activity, can further be broken down into the processor and memory system. The input/output system is physically connected to field devices (e.g., switches, sensors, etc.) and provides the interface between the CPU and the information providers (inputs) and controllable devices (outputs).
To operate, the CPU "reads" input data from connected field devices through the use of its input interfaces, and then "executes", or performs the control program that has been stored in its memory system. Programs are typically created in ladder logic, a language that closely resembles a relay-based wiring schematic, and are entered into the CPU's memory prior to operation. Finally, based on the program, the PLC "writes", or updates output devices via the output interfaces. This process, also known as scanning, continues in the same sequence without interruption, and changes only when a change is made to the control program.
A brief history
The first PLC can be traced back to 1968 when Bedford Associates, a company in Bedford, MA, developed a device called a Modular Digital Controller for General Motors (GM). The MODICON, as it was known, was developed to help GM eliminate traditional relay-based machine control systems. Because relays are mechanical devices, they have limited lifetimes. They are also cumbersome, especially in large applications where thousands of them may exist. With so many relays to work with, wiring and troubleshooting could be quite complicated.
Since the MODICON was an electronic device, not a mechanical one, it was perfect for GM's requirements, as well as for many other manufacturers and users of control equipment. With less wiring, simpler troubleshooting, and easy programming, PLC technology caught on quickly.
Today's PLC
As PLC technology has advanced, so have programming languages and communications capabilities, along with many other important features. Today's PLCs offer faster scan times, space efficient high-density input/output systems, and special interfaces to allow non-traditional devices to be attached directly to the PLC. Not only can they communicate with other control systems, they can also perform reporting functions and diagnose their own failures, as well as the failure of a machine or process.
Size is typically used to categorize today's PLC, and is often an indication of the features and types of applications it will accommodate. Small, non-modular PLCs (also known as fixed I/O PLCs) generally have less memory and accommodate a small number of inputs and outputs in fixed configurations. Modular PLCs have bases or racks that allow installation of multiple I/O modules, and will accommodate more complex applications.
When you consider all of the advances PLCs have made and all the benefits they offer, it's easy to see how they've become a standard in the industry, and why they will most likely continue their success in the future.
Which one is right for you?
So you've learned a little bit about PLCs and have decided that a PLC-based control system is the right choice for you. Now what?
The next step is to select the right system. But how do you do that? Where do you begin when there are so many manufacturers and so many different PLC models?
A drawing of the machine or process is a good start. This can help identify field devices and physical requirements for hardware locations. From the drawing, you can determine how many analog and/or discrete devices you will have. Discrete devices are those that operate in only two states: on and off. Examples of discrete devices include pushbuttons and switches. Analog devices, such as thermocouples, process transducers, and display meters, will supply or accept signals within a specified range, typically 0-10 volts or 4-20 mA.
Once the field device requirements and hardware locations are defined, you can begin the process of choosing a PLC that will meet your requirements. The worksheet on the following page is a basic summary of considerations for determining the type of PLC you will need, regardless of which manufacturers you are evaluating. Armed with this information, the next steps will be selecting, designing, programming, and installing your system.
When choosing a PLC, there are many factors to consider that, if not properly planned for, may affect your system's performance after installation. With proper planning, the selection of a PLC system can be done with relative ease.
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