PROFIBUS Controller SPC 4®-2 LF
100
C79000-G8976-C157-3
7.11 SPC
4-2-Timers
7.11.1 Delay Timer
Description
The delay timer on the SPC 4-2 is implemented as a 24-bit timer. To remain
compatible with SPC 4, the delay timer is limited to 16 bits in the PA mode
(XPB/PA=1).. It is automatically reset and started when a "first-time frame" is
received. The counter is incremented until it is read. At each overrun, an interrupt
(Del-Tim-Overrun) is generated and incremented.
The counter reading must be reset after it is read out
so that no further delay
timer overrun interrupt is generated and so that the system management can
recognize when a second SM-Time frame arrives (for example, if the first SM-Time
frame was lost due to a bus problem), for further details refer to system
management (SM-Time). System management must be capable of handling
possible error situations such as two consecutive second SM-Time frames from
different time masters.
The FAKT_DEL_CLK divider has a range from 64 to 1536.
1
_
_
_
−
=
CLK
DEL
Quarz
CLK
DEL
FAKT
Quartz
FAKT_DEL_CLK DEL_CLK Resolution=1/DEL_CLK
48 MHz
1535
31.25 kHz
32
µ
s
20 MHz
639
31.25 kHz
32
µ
s
2 MHz
63
31.25 kHz
32
µ
s
Table 7-24 : Formula for Calculating FAKT_DEL_CLK
Note
According to PROFIBUS-PA a resolution of 32
µ
s should be selected, the
divider FAKT_DEL_CLK must be set depending on the required quartz
frequency.
When selecting the quartz frequency, the table for the baud rate generator must be
taken into account.
Содержание SIMATIC NET SPC 4-2 LF
Страница 9: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 9 Introduction 1 ...
Страница 11: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 11 Functional Overview 2 ...
Страница 14: ...PROFIBUS Controller SPC 4 2 LF 14 C79000 G8976 C157 3 ...
Страница 15: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 15 Pin Assignment 3 ...
Страница 18: ...PROFIBUS Controller SPC 4 2 LF 18 C79000 G8976 C157 3 ...
Страница 19: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 19 Memory Assignment 4 ...
Страница 32: ...PROFIBUS Controller SPC 4 2 LF 32 C79000 G8976 C157 3 ...
Страница 33: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 33 FLC Interface 5 ...
Страница 50: ...PROFIBUS Controller SPC 4 2 LF 50 C79000 G8976 C157 3 ...
Страница 51: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 51 DP Interface 6 ...
Страница 63: ...ASIC Interface PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 63 ASIC Interface 7 ...
Страница 107: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 107 Asynchronous Interface 8 ...
Страница 114: ...PROFIBUS Controller SPC 4 2 LF 114 C79000 G8976 C157 3 ...
Страница 115: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 115 Synchronous Interface 9 ...
Страница 125: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 125 Clock Pulses 10 ...
Страница 128: ...PROFIBUS Controller SPC 4 2 LF 128 C79000 G8976 C157 3 ...
Страница 129: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 129 Processor Interface 11 ...
Страница 152: ...PROFIBUS Controller SPC 4 2 LF 152 C79000 G8976 C157 3 ...
Страница 153: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 153 Technical Specifications 12 ...
Страница 159: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 159 Package 13 ...
Страница 165: ...Package PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 165 Figure 13 4 Tray Spezification ...
Страница 166: ...PROFIBUS Controller SPC 4 2 LF 166 C79000 G8976 C157 3 ...
Страница 168: ...PROFIBUS Controller SPC 4 2 LF 168 C79000 G8976 C157 3 ...
Страница 169: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 169 Addresses 15 ...
Страница 172: ...PROFIBUS Controller SPC 4 2 LF 172 C79000 G8976 C157 3 ...
Страница 173: ...PROFIBUS Controller SPC 4 2 LF C79000 G8976 C157 3 173 Appendix 16 ...
Страница 178: ...PROFIBUS Controller SPC 4 2 LF 178 C79000 G8976 C157 3 ...