TTI PL-P Serie Manuel D'utilisation page 17

Before a response can be read from an instrument it must be addressed to talk by sending the
Talk Address control code, 14H (TAD) followed by a single character which has the lower 5 bits
corresponding to the unique address of the required instrument, as for the listen address control
code above. Once addressed to talk the instrument will send the response message it has
available, if any, and then exit the talk addressed state. Only one response message will be sent
each time the instrument is addressed to talk.
Talk mode will be cancelled by any of the following interface control codes being received:
Talk mode will also be cancelled when the instrument has completed sending a response
message or has nothing to say.
The interface code 0AH (LF) is the Universal Command and response Terminator (UCT); it must
be the last code sent in all commands and will be the last code sent in all responses.
The interface code 0DH (CR) may be used as required to aid the formatting of commands; it will
be ignored by all instruments. Most instruments will terminate responses with CR followed by LF.
The interface code 13H (XOFF) may be sent at any time by a listener (instrument or controller) to
suspend the output of a talker. The listener must send 11H (XON) before the talker will resume
sending. This is the only form of handshake control supported by ARC.
ARC Interface Control Code List
12H LAD Listen Address for any instrument.
14H TAD Talk Address followed by an address not
belonging to this instrument.
03H UNA Universal Unaddress control code.
04H LNA Lock Non-Addressable mode control code.
18H UDC Universal Device Clear.
02H SAM Set Addressable mode.
03H UNA Universal Unaddress control code.
04H LNA Lock Non-Addressable mode control code.
06H ACK Acknowledge that listen address received.
0AH UCT Universal Command and response
Terminator.
0DH CR Formatting code, otherwise ignored.
11H XON Restart transmission.
12H LAD Listen Address - must be followed by an
address belonging to the required
instrument.
13H XOFF Stop transmission.
14H TAD Talk Address - must be followed by an
address belonging to the required
instrument.
18H UDC Universal Device Clear.
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