BK8x00 - FB Slave COM-Port
With this function block, the PC (TwinCAT or KS8000) can be connected with the BXxxxx via the serial interface. The PC acts as the serial master, and the BXxxxx emulates a BK8x00 with the aid of the function block.
VAR_INPUT
stCOMConfig :ST_COMConfig;
byAddress :BYTE;
byLenDataOut :BYTE;
byLenDataIN :BYTE;
ptDataOut :POINTER TO BYTE;
ptDataIN :POINTER TO BYTE;
WDTime :TIME;
Legend
stComConfig: Structure for selecting the COM parameters
byAddress: BX8x00 address 1-98 (0 and 99 are reserved)
byLenDataOut: data length in [BYTES] (only even numbers are permitted, i.e. 0, 2, 4, ...)
byLenDataIn: data length in [BYTES] (only even numbers are permitted, i.e. 0, 2, 4, ...)
ptDataOut: is connected with ADR and data out
ptDataIn: is connected with ADR and data in
WDTime: error message if no new data are received within the watchdog time (0 ms disable WD)
VAR_OUTPUT
bError :BOOL;
iErrorId :WORD;
Input_Len :BYTE;
Legend
bError: error bit
iErrorId: Error number
Input_Len: number of data that were received
|
Return parameter iErrorId |
Meaning |
|---|---|
|
0 |
No error |
|
1 |
Watchdog error, if greater than 0 ms (WD disable if 0 ms) |
|
100dec |
Error during opening of the COM port |
|
101dec |
Error during sending of data |
|
103dec |
Internal receive buffer overflow |
|
104dec |
Data exceed the PLC buffer capacity (more than 500 bytes) |
|
105dec |
Data cannot be copied into the PLC buffer |
|
200dec |
CRC error |
Hardware
RS232 communication PIN assignment
|
BX COM 1 RS232 |
BX COM 2 RS232 |
PC COM interface |
|---|---|---|
|
2 |
8 |
2 |
|
3 |
7 |
3 |
|
5 |
5 |
5 |
RS485 communication PIN assignment
FB settings: When using the RS485 connection it is important that the stCOMConfig variable is set to 1 and that the COM2 interface is selected.
|
BX COM 2 RS485 |
PC COM port (e.g. RS485 card W&T #13601, 2-wire, without echo, automatic) |
|---|---|
|
1 |
1 - 2 bridges |
|
6 |
6 - 7 bridges |
ST sample program for BXxxx
Download (sample file)
System Manager file for TwinCAT as master. As shown in the figure, a Bus Coupler with Bus Terminals is configured. In this case, the type and number of Bus Terminals determines the data length. In principle, the type of Bus Terminal is irrelevant. Sample:
- 2 x KL3002 results in 4 words of input
- 2 x KL4002 results in 4 words of output
Required material:
- BX3100 + Bus Terminal
- PC with RS232 interface and TwinCAT from version 2.9, serial cable, PIN assignment: see above