164
APPX
Appendix 4 Processing Time
Appendix 4
Processing Time
This section describes bus cycle time and transmission delay time.
Bus cycle time
When only one DP-Master is deployed
■
Calculation formula of bus cycle time (Bc)
The following calculation formula provides bus cycle time (Bc) of the DP-Master.
The symbol in [ ] indicates the unit.
n = The number of DP-Slaves
Max (A, B) = The larger of A and B
*1 A value set in "Min. slave interval" of the "Master Settings" window of PROFIBUS Configuration Tool.
*2 The max_Tsdr value specified in the GSD file of DP-Slaves.
*3 The unit TBit (Bit Time) defines "1" as the time it takes to send 1 bit data.
The actual processing time depends on the transmission speed as follows.
When the transmission speed is 1.5Mbps
1[TBit] = 1
÷
(1.5
×
10
6
) = 0.667
×
10
-6
[s]
When the transmission speed is 12Mbps
1[TBit] = 1
÷
(12
×
10
6
) = 0.083
×
10
-6
[s]
*4 The Tsdi value specified in the GSD file of the FX5-DP-M.
The Tsdi value depends on the transmission speed as follows.
For the unit TBit, refer to *3.
Item
Description
MSI[s]
Minimum required time for polling cycle (Min. slave interval)
Pt(i)[s]
(Polling cycle of ith station) = Treq(i) + max_Tsdr(i) + Tres(i)
• Treq(i)[s] = (Request transmission time of ith station) = {(Number of output bytes to ith station) + 9}
×
11[bit]
÷
(Transmission
speed[bps])
• max_Tsdr(i)[s] = (Response time of ith station[TBit])
÷
(Transmission speed[bps])
• Tres(i)[s] = (Response transmission time of ith station) = {(Number of input bytes from ith station) + 9}
×
11[bit]
÷
(Transmission
speed[bps])
Tsdi(M)[s]
(Request/response processing time of DP-Master (FX5-DP-M)[TBit])
(Transmission speed[bps])
Lr[s]
(Data refresh time) = 5.50
×
10
-6
+ Number of DP-Slaves
×
150
×
10
-6
Transmission speed
Request/response processing time of DP-Master
9.6kbps]
70TBit
19.2kbps
93.75kbps
187.5kbps
500kbps
150TBit
1.5Mbps
200TBit
3Mbps
250TBit
6Mbps
450TBit
12Mbps
800TBit
Bc[s] = Max (MSI,
(Pt(i) + Tsdi(M)) + Lr)
n
i=1
Содержание FX5-DP-M
Страница 1: ...MELSEC iQ F FX5 User s Manual PROFIBUS ...
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Страница 12: ...10 INDEX 168 REVISIONS 170 WARRANTY 171 TRADEMARKS 172 ...
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Страница 19: ...1 DESCRIPTION 17 1 MEMO ...
Страница 100: ...98 9 PROGRAMMING 9 2 DP Master settings DP Slave FDL address 2 ...
Страница 101: ...9 PROGRAMMING 9 2 DP Master settings 99 9 DP Slave FDL address 3 ...
Страница 108: ...106 9 PROGRAMMING 9 8 Program Example of the Global Control Function ...
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Страница 110: ...108 9 PROGRAMMING 9 8 Program Example of the Global Control Function ...
Страница 112: ...110 9 PROGRAMMING 9 9 Program Example of Acyclic Communication Acyclic Communication ...
Страница 114: ...112 9 PROGRAMMING 9 10 Program Example of the Alarm Acquisition Function ...
Страница 169: ...APPX Appendix 4 Processing Time 167 A MEMO ...
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