Siemens Simatic S7-400

Con󹪝guration Data of the 3964(R) procedure
With the CP 440: Point-to-Point Communication, Parameter Assignment interface, specify
the parameters for the physical layer (layer 1) and the data-link layer (layer 2) of the 3964(R)
procedure. Below you will 󹪝nd a detailed description of the parameters.
Note
The 3964(R) procedure can only be used in four-wire mode.
Protocol
The following table describes the protocol.
Table 5-10 3964(R) Protocol
Parameter Description Default Value
3964 with default
values and no
block check
• The protocol parameters are set to default values.
• If the CP 440 recognizes the string DLE ETX, it stops receiving and
sends a DLE to the communication partner if the block was re‐
ceived undamaged, or an NAK if it was damaged.
3964(R) with default values
and block check:
CDT = 220 ms
ADT = 2000 ms
Connection attempts = 6
Transmission attempts = 6
3964R with default
values and block
check
• The protocol parameters are set to default values.
• If the CP 440 recognizes the string DLE ETX BCC, it stops receiving.
The CP 440 compares the block check character (BCC) received
with the length parity calculated internally. If the BCC is correct and
no other receive errors have occurred, the CP 440 sends the code
DLE to the communication partner (the NAK code is sent if an error
occurs).
3964 assignable
without block
check
• The protocol parameters are programmable.
• If the CP 440 recognizes the string DLE ETX, it stops receiving and
sends a DLE to the communication partner if the block was re‐
ceived undamaged, or an NAK if it was damaged.
3964R assignable
with block check
• The protocol parameters are programmable.
• If the CP 440 recognizes the string DLE ETX BCC, it stops receiving.
The CP 440 compares the block check character (BCC) received
with the length parity calculated internally. If the BCC is correct and
no other receive errors have occurred, the CP 440 sends the code
DLE to the communication partner (the NAK code is sent if an error
occurs).
Con󹪝guring and Parameter Assignment the CP 440
5.4 Con󹪝guration data
Point-to-point connection CP 440 Installation and Parameter Assignment
64 Equipment Manual, 03/2022, A5E00057742-AE