MGR10 A/B/C - Revision : I (for 7.0 software revision)
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The 5 General Interface Management Lines are;
REN Remote
Enable
This is used only by the System Controller to enable devices to be subsequently placed in the
remote programming mode. When true, all listeners capable of remote operation are placed in
remote when addressed to listen. When false, all devices return to local operation. All devices
capable of both remote and local operation must monitor REN at all times. Devices must
respond to REN within 100uS.
The REN command is the only command that will put the instrument into remote mode. The
front-panel keys are disabled, and the ‘Rem’ legend appears on the display. The ‘Lstn’ and
‘Talk’ legends indicate when the instrument is addressed.
The instrument may be returned to local operation by sending the GTL command while the
instrument is addressed to listen.
IFC Interface
Clear
This is used only by the System Controller to halt current operations (communications) on the
bus (i.e. unaddress all talkers and listeners and disable Serial Poll - the idle state). All devices
must monitor IFC at all times and respond within 100uS (minimum pulse width for IFC).
EOI End
Or
Identify
When ATN is true the EOI line is used by a controller to execute a parallel poll. When ATN is
false, the EOI line is used by an active talker to indicate the last byte of a data message.
SRQ Service
Request
This is used by one or more devices to indicate the need for attention and can act as an
interruption of the current sequence of events. Typically SRQ indicates data is ready to transmit
and/or an error condition (e.g. syntax error, overload, trigger too fast etc.) exists. The controller
can mask the SRQ interrupt and must perform a Serial Poll of devices (when there is more than
one) to determine who requested service and why.
ATN Attention
All devices must monitor ATN at all times and respond to it within 200nS. When true ATN
places the interface in the Command Mode where all devices accept (handshake) data on the
DIO lines and interpret it as it Commands (see Multi-wire Interface Messages below). When
false ATN places the interface in the Data Mode where the active talker sources device
dependent Data to all active listeners. Addresses are sent over the bus during the Command
Mode.
