Siemens SIMATIC NET SPC 4-2 LF, Руководство пользователя

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PROFIBUS Controller SPC 4®-2 LF
156
C79000-G8976-C157-3
12.3 Power Consumption
The power consumption of a large-scale integrated digital module such as the SPC
4-2 depends to a great extent on the selected mode. The power supply, the
external clock frequency, data transmission rate and type and frequency of access
to the memory interface determine the current consumption of the chip. The
information on the current consumption below can therefore only be a guideline
and the actual values must be measured in each individual case.
Power supply VDD = 5 V (with the exception of the information in the bottom line
where VDD = 3.3 V)
All information on current consumption in [mA]
Clock Frequency / Mode 2 MHz 4 MHz 8 MHz 24 MHz 48 MHz
Reset 0.25 0.7 1.4 2.9 5
Memory Access 4 7 11 23 43
Data exchange 9.6 Kbps 5.4 - - - -
Data exchange 19.2 Kbps - 4.5 - - -
Data exchange 500 Kbps - 5.5 - - 32
Data exchange 1.5 Mbps - - - - 38
Data exchange 12 Mbps - - - - 55
Data exchange 31.25 Kbps
VDD =
3.3 V
3.6 - - - -
Table 12-3: Current Consumption
The values shown in the table are typical values obtained by measurement on
several chips in various modes:
● Reset
RESET input active, chip is in the reset status
● Memory access
The connected CPU reads and writes the SPC 4-2 internal RAM cyclically.
● Data exchange
The SPC 4-2 is in the data exchange status, an external master exchanges
data with the slave cyclically. The input/output data is read from or written to
the SPC 4-2 memory cyclically by the connected CPU.