Siemens SIMATIC CP 440, Руководство пользователя

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Configuring and Parameterizing the CP 440
5-7
Point-to-point connection CP 440 Installation and Parameter Assignment
A5E00057742-02
Protocol Parameters
The table below describes the protocol parameters.
Table 5-5 Protocol Parameters (ASCII Driver)
Parameter Description Value Range Default Value
End ID of a
Receive
Message Frame Specifies the criterion that
indicates the end of each message
frame.
•
On Expiry of Character
Delay Time
•
On Receipt of Fixed
Number of Characters
•
On Receipt of End
Character
•
On Expiry of
Character
Delay Time
Character Delay
Time The character delay time defines
the maximum permitted time
between 2 consecutively received
characters. 1 to 65535 ms
The shortest character delay
time depends on the
transmission rate
•
4 ms
Monitoring Time
for Missing
End ID The character delay time is used
as the monitoring time for a
missing end code. This applies to
the following settings for the end
code
– On Receipt of Fixed
Number of Characters
– On Receipt of End
Character
bps
300
600
1200
2400
4800
9600
19200
38400
57600
76800
115200
Character time
delay (ms)
130
65
32
16
8
4
2
1
1
1
1
1st End ID
1
First end code.
•
7 data bits
2
:
0 to 7FH (hex)
•
8 data bits
2
:
0 to FFH (hex)
•
3 (03H =
ETX)
2nd End ID
1
Second end code, if specified.
You can parameterize the following
for the end code:
– 1st end ID AND
2nd end ID
– 1st end ID OR 2nd end ID
•
7 data bits
2
:
0 to 7FH (hex)
•
8 data bits
2
:
0 to FFH (hex)
•
0
Message Frame
Length
3
When the end criterion is “fixed
message frame length”, the
number of bytes making up a
message frame is defined. 1 to 200 (bytes)
•
200