Communication Mode; Synchronization; Remote/Local Control - Iwatsu VOAC760 Manual

2.5.3

Communication mode

This instrument uses the full-duplex communication method. Therefore, the instrument may start
sending the response message even while it is receiving the message. Normally, this is not a problem
since the data receive buffer is provided. However, if any problem is foreseen, the flow control must
be taken into consideration.
This instrument performs the hardware flow control. The instrument does not have other flow controls
and the hardware flow control cannot be made invalid.
With this instrument, when internal processing lacks the space to obtain input data, the RTS signal is
set to low level. When there is room for this processing, the RTS signal is set to high level.
This instrument is unable to transmit data when the CTS signal is at low level.
2.5.4

Synchronization

This instrument can use only hardware flow control for the synchronization in the serial
communication with the external instrument.
To perform the synchronization with the software, it is recommended to create a remote program that
the last message unit of the message to be sent to this instrument is used as a query (command that
requests the response message from this instrument) and the next message is sent after the
response has been received from this instrument.  OPC? query (see section 3.4.5), etc. can be used.
2.5.5

Remote/local control

a. Local mode
In the local mode, operation of the instrument is controlled through panel key operation.
The REMOTE LED is off.
This instrument enters the local mode when the power is turned on.
The following two kinds of methods are provided to return the mode from the remote mode to the local
mode.
 Turn off the power, and turn it on again.
 Press the LOCAL ([RES]) key.
b. Remote mode
In the remote mode, operation of the instrument is controlled by messages sent through the interface.
All panel key entries except for the LOCAL ([SHIFT]) key become invalid.
The REMOTE icon is lit during remote control.
If the instrument receives the message from the external instrument, it then enters the remote mode.
At this time, as soon as the instrument receives the start byte of the message correctly, it then enters
the remote mode.
c. Local lock out mode
This instrument does not support local lock out mode other than for the GPIB interface. When a lock
out operation is necessary, use the GPIB interface.
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