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Updated Home (markdown)

Michele Cattafesta
2017-08-31 21:21:52 +01:00
parent d920d12b09
commit 10871fa017
1 changed files with 67 additions and 42 deletions
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109
Home.md

@@ -18,7 +18,8 @@ To get started with S7.Net you have to download and include the S7.Net.dll in yo
To create an instance of the driver you need to use this constructor:
public Plc(CpuType cpu, string ip, Int16 rack, Int16 slot)
• Cpu: this specify what CPU you are connecting to. The supported CPU are:
* Cpu: this specify what CPU you are connecting to. The supported CPU are:
public enum CpuType {
S7200 = 0,
S7300 = 10,
@@ -26,9 +27,10 @@ public enum CpuType {
S71200 = 30,
S71500 = 40,
}
• Ip: this contains the IP address of the CPU of external Ethernet card
• Rack: this contains the rack of the plc, that you can find in hardware configuration in Step7
• Slot: this is the slot of the CPU, that you can find in hardware configuration in Step7
* Ip: this contains the IP address of the CPU of external Ethernet card
* Rack: this contains the rack of the plc, that you can find in hardware configuration in Step7
* Slot: this is the slot of the CPU, that you can find in hardware configuration in Step7
Example:
This code creates a Plc object for a S7-300 plc at the IP address 127.0.0.1, that it’s localhost, for a plc that it’s in rack 0 and a cpu that it’s in slot 2 of the hardware configuration:
@@ -37,7 +39,9 @@ Plc plc = new Plc(CpuType.S7300, "127.0.0.1", 0, 2);
## Connecting to the PLC
public ErrorCode Open()
For example this line of code open the connection:
plc.Open();
## Disconnecting from the PLC
@@ -45,12 +49,14 @@ plc.Open();
public void Close()
For example this closes the connection:
plc.Close();
 
## Error handling
The Open() method returns an ErrorCode to check if the operation was successful. You should always check that it returns ErrorCode.NoError.
These are the types of errors:
public enum ErrorCode
{
NoError = 0,
@@ -67,20 +73,30 @@ public enum ErrorCode
## Global error handling
Not all methods returns an error. You can check for
public ErrorCode LastErrorCode
and
public string LastErrorString
on every methods that you execute, in order to catch errors while running the driver.
 
## Check PLC availability
To check if the plc is available you can use the property
public bool IsAvailable
When you check this property, the driver will send a ping to the plc and returns true if the plc responds to the ping, false otherwise.
Check PLC connection
## Check PLC connection
Checking the plc connection is trivial, because you have to check if the PC socket is connected but also if the PLC is still connected.
The property that you have to check in this case is this:
public bool IsConnected
This property can be checked after you called the method Open(), to check if the connection is still alive.
 
@@ -93,7 +109,8 @@ public byte[] ReadBytes(DataType dataType, int db, int startByteAdr, int count)
public ErrorCode WriteBytes(DataType dataType, int db, int startByteAdr, byte[] value)
This reads up to 200 bytes (actual limit of the protocol) from a memory location that you determine.
• dataType: you have to specify the memory location with the enum DataType
* dataType: you have to specify the memory location with the enum DataType
public enum DataType
{
Input = 129,
@@ -103,16 +120,17 @@ public enum DataType
Timer = 29,
Counter = 28
}
• db: this is the address of the dataType, for example if you want to read DB1, this field is “1”; if you want to read T45, this field is 45.
• startByteAdr: this is the address of the first byte that you want to read, for example if you want to read DB1.DBW200, this is 200.
• count: this contains how many bytes you want to read. It’s limited to 200 bytes and if you need more, you must use recursion.
• Value[]: array of bytes to be written to the plc.
* db: this is the address of the dataType, for example if you want to read DB1, this field is “1”; if you want to read T45, this field is 45.
* startByteAdr: this is the address of the first byte that you want to read, for example if you want to read DB1.DBW200, this is 200.
* count: this contains how many bytes you want to read. It’s limited to 200 bytes and if you need more, you must use recursion.
* Value[]: array of bytes to be written to the plc.
Example:
This method reads the first 200 bytes of DB1:
var bytes = plc.ReadBytes(DataType.DataBlock, 1,0,200);
Example with recursion:
private List<byte> ReadMultipleBytes(int numBytes, int db, int startByteAdr = 0)
{
List<byte> resultBytes = new List<byte>();
@@ -138,7 +156,8 @@ public object Read(DataType dataType, int db, int startByteAdr, VarType varType,
public ErrorCode Write(DataType dataType, int db, int startByteAdr, object value)
• dataType: you have to specify the memory location with the enum DataType
* dataType: you have to specify the memory location with the enum DataType
public enum DataType
{
Input = 129,
@@ -148,24 +167,27 @@ public enum DataType
Timer = 29,
Counter = 28
}
• db: this is the address of the dataType, for example if you want to read DB1, this field is “1”; if you want to read T45, this field is 45.
• startByteAdr: this is the address of the first byte that you want to read, for example if you want to read DB1.DBW200, this is 200.
• varType: specify the data that you want to get your bytes converted.
* db: this is the address of the dataType, for example if you want to read DB1, this field is “1”; if you want to read T45, this field is 45.
* startByteAdr: this is the address of the first byte that you want to read, for example if you want to read DB1.DBW200, this is 200.
* varType: specify the data that you want to get your bytes converted.
public enum VarType
{
Bit,
Byte,
Word,
DWord,
Int,
DInt,
Real,
String,
Timer,
Counter
Bit,
Byte,
Word,
DWord,
Int,
DInt,
Real,
String,
Timer,
Counter
}
• count: this contains how many variables you want to read. It’s limited to 200 bytes and if you need more, you must use recursion.
• Value: array of values to be written to the plc. It can be a single value or an array, the important is that the type is unique, for example array of double, array of int, array of shorts, etc..
* count: this contains how many variables you want to read. It’s limited to 200 bytes and if you need more, you must use recursion.
* Value: array of values to be written to the plc. It can be a single value or an array, the important is that the type is unique, for example array of double, array of int, array of shorts, etc..
Example:
This method reads the first 20 DWords of DB1:
@@ -179,7 +201,7 @@ public object Read(string variable)
public ErrorCode Write(string variable, object value)
• variable: specify the variable to read by using strings like “DB1.DBW20”, “T45”, “C21”, “DB1.DBD400”, etc.
* variable: specify the variable to read by using strings like “DB1.DBW20”, “T45”, “C21”, “DB1.DBD400”, etc.
Example:
This reads the variable DB1.DBW0. The result must be cast to ushort to get the correct 16-bit format in C#.
@@ -234,15 +256,16 @@ public void ReadClass(object sourceClass, int db, int startByteAdr = 0)
public ErrorCode WriteClass(object classValue, int db, int startByteAdr = 0)
• sourceClass: instance of the class that you want to assign the values
• db: index of the DB to read
• startByteAdr: specified the first address of the byte to read (the default is zero).
* sourceClass: instance of the class that you want to assign the values
* db: index of the DB to read
* startByteAdr: specified the first address of the byte to read (the default is zero).
Example:
Define a DataBlock in the plc like:
![struct](https://github.com/killnine/s7netplus/blob/master/Documentation/struct.png)
Then add a struct into your .Net application that is similiar to the DB in the plc:
public class TestClass
{
public bool varBool0 { get; set;}
@@ -267,49 +290,51 @@ public class TestClass
}
then you add the code to read or write the complete struct
// reads a struct from DataBlock 1
TestClass testClass = new TestClass();
plc.ReadClass(testClass, 1);
 
Value conversion between C# and S7 plc
• Read S7 Word:
* Read S7 Word:
ushort result = (ushort)plc.Read("DB1.DBW0");
• Write S7 Word:
* Write S7 Word:
ushort val = 40000;
plc.Write("DB1.DBW0", val);
• Read S7 Int / Dec, you need to use the method ConvertToShort():
* Read S7 Int / Dec, you need to use the method ConvertToShort():
short result = ((ushort)plc.Read("DB1.DBW0")).ConvertToShort();
• Write S7 Int / Dec, you need to use the method ConvertToUshort():
* Write S7 Int / Dec, you need to use the method ConvertToUshort():
short value = -100;
plc.Write("DB1.DBW0", value.ConvertToUshort());
• Read S7 DWord:
* Read S7 DWord:
uint result = (uint)plc.Read("DB1.DBD40");
• Write S7 DWord:
* Write S7 DWord:
uint val = 1000;
plc.Write("DB1.DBD40", val);
• Read S7 Dint, you need to use ConvertToInt():
* Read S7 Dint, you need to use ConvertToInt():
int result2 = ((uint)plc.Read("DB1.DBD60")).ConvertToInt();
• Write S7 Dint:
* Write S7 Dint:
int value = -60000;
plc.Write("DB1.DBD60", value);
• Read S7 Real, you need to use ConvertToDouble():
* Read S7 Real, you need to use ConvertToDouble():
double result = ((uint)plc.Read("DB1.DBD40")).ConvertToDouble();
• Write S7 Real, you need to use ConvertToInt():
* Write S7 Real, you need to use ConvertToInt():
double val = 35.687;
plc.Write("DB1.DBD40", val.ConvertToUInt());
• Read bool from byte
* Read bool from byte
byte myByte = 5; // 0000 0101
myByte.SelectBit(0) // true
myByte.SelectBit(1) // false