Siemens SITOP BUF8600, Manual

Page: 157 / 252

Engineering and remote access
7.4 SIMATIC STEP 7
PSU8600power supply systems
Manual, 04.2016, A5E35883207-7-76
157
● Buffer component disabled via control command
Buffer modules with double-layer capacitors can be deactivated using a control
command. If the parameters are to be activated, then all of the buffer components in the
system are deactivated. System buffering using buffer components is therefore
deactivated; this function can be used for smoothly commissioning the system.
Note
Deactivation via control command is independent of deactivation via control contact, and
further, has the same priority as deactivation using the control contact. This means that
both options to activate the buffer components (control command and control contact)
must be set at the same time (this corresponds to the default setting), in order to allow
the system to be buffered.
● Enable LONGLIFE operating mode
In order to increase the service life of the buffer modules with double-layer capacitors,
these can be operated in the "LONGLIFE" mode with reduced buffer capacity. When the
buffer module is completely charged, power failures of up to a maximum of 3 s
(6EP4293-8HB00-0XY0) or up to a maximum of 8 s (6EP4295-8HB00-0XY0) can be
buffered with a load current of 40 A.
● Threshold value for sufficient buffer readiness
The charge state of the buffer components in the system can be interrogated using the
threshold value. The value as a percentage refers to the maximum amount of energy that
can be stored; for several buffer components in the system, the sum of the maximum
amounts of energy that can be stored. This means that it can be ensured that a process
is only started if sufficient buffer energy is available to buffer a possible power failure.
● Enable short-time interruption at output 1
If the function is activated, then when the power supply returns during buffer operation,
the voltage at output 1 is interrupted for a time that can be parameterized. This can be
used to automatically restart a PC, which was run down after the start of buffer operation
to back up data, when the power returns.
● Dead time for start of short-time interruption
Using the parameter, the time is defined that must elapse until after the start of buffer
operation an alarm message "Buffer operation" is output. This means that very short
power failures can be easily buffered, and the alarm message suppressed. For power
failures that last for a longer period of time, the alarm message can then be used to
initiate other specific measures, for example, safely running down a PC.
● Waiting time until short-time interruption
The parameter is used to define the minimum time that must elapse after the "Buffer
operation" alarm message, before the output voltage at output 1 is interrupted when the
power supply returns during buffer operation. For instance, this can be the time that a PC
requires to safely run down.
● Duration of short-time interruption
The parameter is used to define the time for which output 1 is interrupted during buffer
operation when the power returns (for example to restart a PC after it has been run
down).