Siemens SIMATIC CP 541, Руководство пользователя

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C-5
Communications Processor CP 541
EWA 4NEB 812 6188-02
Table C-1 SL2 Parameters, continued
Parameter
1
Meaning Values
SET
(T
SET
)
0 ... 494
*
Setup time
The setup time is the time which may elapse between an event and the reaction to
the event.
The formula is: (SDT 2
*
35)/2
w
SET
u
(SDT 1
*
35)/2.
This parameter must be set identically in all stations.
ST
(T
SL
)
50 ... 4095
*
Slot time
The slot time specifies how long a sending station must wait until the addressed
station reacts. The type of message concerned is not significant.
The formula is: ST
w
(SDT 2
)
15).
This parameter must be set identically in all stations.
SDT 1
(min T
SDR
)
11 ... 255
*
Station delay time 1 (shortest protocol processing time)
Station delay time 1 is the minimum time elapsing between the sending or receiving
of the last bit of a message and the sending or receiving of the first bit of a subse-
quent message.
The formula is: SDT 1
t
(35
)
2 SET).
The parameter must be set identically in all stations.
SDT 2
(max T
SDR
)
35 ... 1023
*
Station delay time 2 (greatest protocol processing time)
Station delay time 2 is the maximum time elapsing between the sending or receiv-
ing of the last bit of a message and the sending or receiving of the first bit of a sub-
sequent message.
The formula is: SDT 1
t
(35
)
2 SET)
v
SDT 2
v
(ST
*
15)
This parameter must be set identically in all stations.
1
Designations given in parentheses comply with DIN 19245.
*
Specify the value in bit times. A bit time is the time elapsing during transmission of one bit. It is the reciprocal of the
baud rate.
Parameters TLN, STA, BDR, HSA, TRT, SET, ST, SDT 1 and SDT 2 are
referred to as basic parameters. You must set these basic parameters identi-
cally in all stations in the entire SINEC L2, except for TLN and STA.
Depending on the station status (STA) you need not specify all basic parame-
ters. The necessary basic parameters are given in Table C-2.
Table C-2 Necessary Basic Parameters According to Station Status (STA)
Station Status TLN STA BDR HSA TRT SET ST SDT 1 SDT 2
STA = AKT X X X X X X X X X
STA = PAS X X X X X
Basic Parameters
Necessary Basic
Parameters
Parameters of DB1