2014-
02
28
Commands
Example of logged lines
The following appears in the window:
0000029.987 CH1 rsp BUS 01 s:0 l:0005 64.03.03.03.03
0000029.845 BUS req CH1 01
Meaning of logged lines
When the time is 0000029.845, the bus sends the command 01 (=SF) to channel 1 of the
IDENTControl Compact. When the time is 0000029.987, the IDENTControl Compact sends
the response with the data packet to the bus.
7.6
Communication via TCP/IP
7.6.1
Data exchange via TCP/IP
TCP/IP is a widely used communications protocol. TCP/IP is not classed as an industrial
Ethernet protocol, but is used in industrial environments. The advantage of the TCP/IP is that
you can use most programming languages to operate the control unit without requiring
additional protocol stacks.
The IDENTControl Compact is a TCP/IP
server
. Each function must be actuated by a
command from the
client
(control software).
Communication occurs via TCP port 10000: The IDENTControl Compact waits for a
connection to be established to port 10000 and responds to incoming commands. Knowledge
of TCP/IP sockets is necessary in order to program the control software.
The illustration shows the basic communication flow:
Command
Time stamp Sender Message type Receiver Command Status Data length Data
0000029.987 CH1
rsp
BUS
01
s:0
l:0005
64.03.03.0
3.03
0000029.845 BUS
req
CH1
01
Byte 0
Telegram length, high byte [(N+1) div 256]
Byte 1
Telegram length, low byte [(N+1) mod 256]
Byte 2
Command code
Byte 3
Channel / Toggle bit = 0
Byte 4
Parameter
Byte 5
Parameter
Byte 6
Write data
...
...
Byte N
Write data
Control software
(client)
IDENTControl Compact
(server)
Establishment of
connection on
TCP/IP layer
Tear-down of
connection
Data exchange
Data exchange
on TCP/IP layer
Establishment of
connection on
TCP/IP layer
Tear-down of
connection
on TCP/IP layer
