FB_EcGetSlaveTopologyInfo
The function block FB_EcGetSlaveTopolgyInfo can be used to determine topology information.
Inputs
VAR_INPUT
sNetId : T_AmsNetId; (*AmsNetId of the EtherCAT master device*)
pAddrBuf : POINTER TO ARRAY [0..EC_MAX_SLAVES] OF ST_TopologyDataEx; (*Contains the address of the buffer the topology data are copied to.*)
cbBufLen : UDINT; (*Size of the buffer pAddrBuf. The size of the buffer must be at least nSlave * 64 Bytes*)
bExecute : BOOL; (*Function block execution is triggered by a rising edge at this input*)
tTimeout : TIME; (*States the time before the function is cancelled*)
END_VAR
Name | Type | Description |
|---|---|---|
sNetId | T_AmsNetId | String containing the AMS network ID of the EtherCAT master device. (Type: T_AmsNetId) |
pAddrBuf | POINTER TO ARRAY | Address of an array of structures of type ST_TopologyDataEx, which contains the topology data. |
cbBufLen | UDINT | Maximum available buffer size (in bytes) for the data to be read |
bExecute | BOOL | The function block is activated by a positive edge at this input. |
tTimeout | TIME | Maximum time allowed for the execution of the function block. |
Outputs
VAR_OUTPUT
bBusy : BOOL;
bError : BOOL;
nErrId : UDINT;
nSlaves : UINT;
END_VAR
Name | Type | Description |
|---|---|---|
bBusy | BOOL | This output is set when the function block is activated, and remains set until a feedback is received. |
bError | BOOL | This output is set after the bBusy output has been reset when an error occurs in the transmission of the command. |
nErrId | UDINT | Supplies the ADS error code associated with the most recently executed command if the bError output is set. Error 1798 (0x706) indicates a null pointer at the buffer address. Error 1797 (0x705) indicates inadequate buffer size. |
nSlaves | UINT | The number of slaves connected to the master. |
Requirements
Development environment | Target platform | PLC libraries to include |
|---|---|---|
TwinCAT v3.1.0 | PC or CX (x86, x64, ARM) | Tc2_EtherCAT |