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8-7-4. Using the local bus
The time-out of communication between the Personal computer and
master unit should be longer when the local bus is used. The
communication time is influenced by the cable length. Check it and
determine the time-out value.
CAUTION
General description about communication
When you are going to control several PSF Series power supply units
from a Personal computer, the potential of the frames of the power supply
units must be equal to that of the Personal computer frame. If those
potentials are different, you may receive electric shocks or the Personal
computer may be broken.
Be very careful.
8-8. Communication commands
・
Every communication command consists of general alphanumeric
characters and symbols and has a header, which is the abbreviation
of a function. Parameters consist of an integer (NR1) and decimal
places (NR2). Parameters following the tenth character are ignored.
Decimal places are rounded off according to the actual setting
resolution. The response contains no header. Only parameters
are sent in response.
・
LF (0
×
0A) is used as the delimiter, which indicates the end of data.
Multi-commands consisting of several continuous commands are not
applicable to communication of the PSF Series power supply unit.
Thus, commands must be separated with delimiters. If delimiters are
used, the interface unit automatically controls the flow of communication.
Communication commands are accepted, whether they are written in
capital letters or small letters.
・
Use the address command
“:ADDR” to specify a system address of
the slave unit when communicating with the slave unit in the local
bus from the Personal computer. Since address 1 has been set by
default, the system address of the master unit is to be specified.
・
A command only applicable to the two-output model (PSF-400L2)
causes an error, if it is used for a one-output model (PSF-400L and
-800L). If a command is used for either channel,
“:A” or “:B” should
be added to the command to specify the channel.
・
An error occurs if a command causing a competitive operation is
sent while the sequence, tracking or external control function is
working.
