NF ZM2371, Instruction Manual

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5.1 Preparations Before Use
5-9 ZM2371/ZM2372
5.1.3.4 Difference between RS-232 and USB/GPIB, and Precautions
The RS-232 is different from USB and GPIB in the following points:

RS-232 is connected to the controller in one-to-one relation.
Multiple devices cannot be connected in parallel to one port.

GPIB own functions cannot be used. The following shows an example.
Device clear (DCL
､
SDC) message
GTL (Go To Local) message
LLO (Local Lockout) message
GET (Group Execute Trigger) message
REN (Remote Enable) message
SRQ (Service Request) and serial polling
END message (EOI signal as a message terminator)

Remote/Local switching operation is different.
When the
ZM2371 / ZM2372
receives a command via RS-232, it goes in the remote state
and the operation from the panel is disabled.
Press the
_ LOCAL _
key to return to the local state, and the operation from the panel is
enabled. Also use the key lock function when the panel operation is to be disabled.

Clear the reception buffer before starting the communication.
With the RS-232 communication path opened by the controller, turning on/off the power of
ZM2371 / ZM2372
, or connecting/disconnecting the RS-232 connector causes abnormal
data to enter the reception buffer in the controller. Accordingly, when the communication
is started or restarted with the program on the controller, be sure to execute initialization
that includes the clear of reception buffer before performing usual operation.