Read CTE
Original instructions
About us
Description
A read CTE operation reads a specified number of bytes from the Ethernet configuration extension table in the specified buffer of PLC memory. These bytes start with a byte offset at the CTE table start. The CTE table contents are displayed in the DATABUF output parameter. To program an MBP_MSTR block to perform a clear remote statistics operation, use function code 11.
Network Implementation
A read CTE operation can be performed on TCP/IP Ethernet and SY/MAX Ethernet networks.
Control Block Usage for TCP/IP Ethernet
Register
Meaning
CONTROL[1]
11 = read CTE
CONTROL[2]
Indicates the error status
CONTROL[3]
The length setting: a value from 12 to 37
CONTROL[4]
No significance
CONTROL[5]
Routing register
Least significant byte = mapping index
Either a value displayed in the byte of the register or is not used.
or Most significant byte = network adapter module slot
CONTROL[6]...
CONTROL[9]
No significance
Control Block Usage for SY/MAX Ethernet
Register
Meaning
CONTROL[1]
11 = read CTE
CONTROL[2]
Indicates the error status
CONTROL[3]
Number of words transferred
CONTROL[4]
Byte offset in the PLC register structure, specifying from where the CTE bytes are read
CONTROL[5]
Routing register
MSB: slot of the NOE module
CONTROL[6]
...
CONTROL[9]
Terminator: FF hex
CTE Indicator Implementation (DATABUF)
The values in the CTE table are displayed in the DATABUF output when a CTE read operation is implemented. The registers display the following CTE data:
CTE indicator implementation (DATABUF):
Parameter
Register
Contents
Frame type
DATABUF[0]
1 = 802.3
2 = Ethernet
IP address
DATABUF[1]
First byte of the IP address
DATABUF[2]
Second byte of the IP address
DATABUF[3]
Third byte of the IP address
DATABUF[4]
Fourth byte of the IP address
Lower netmask
DATABUF[5]
Most significant word
DATABUF[6]
Least significant word
Gateway
DATABUF[7]
First byte of the gateway
DATABUF[8]
Second byte of the gateway
DATABUF[9]
Third byte of the gateway
DATABUF[10]
Fourth byte of the gateway