Measurement Computing Serial488A - Manual (Page 36)

3.2
If the IEEE device has been addressed to talk but does not respond or finish
transmission by the time additional characters are received into the circular serial
input buffer, the talk sequence will be aborted to allow additional serial information to
be sent to the IEEE device.
3.2 Serial and IEEE Terminator Substitution
The Serial488A can be configured to provide serial to IEEE 488 and IEEE 488 to
serial terminator substitution. This is useful when interfacing a serial host which only
issues carriage return [CR] as an output terminator to an IEEE peripheral which
expects a carriage return followed by a line feed [CR-LF].
In this previous example, the serial terminator should be selected for CR Only
while the IEEE terminator is set for CR-LF. When a serial CR character is received it
is discarded and substituted with an IEEE CR followed by an IEEE LF. In the IEEE to
serial direction, the IEEE CR is unconditionally discarded. Upon receipt of the IEEE
LF a serial CR is substituted.
The Serial488A can be made totally data transparent by setting both the serial
and IEEE terminators to be CR Only or LF Only. Refer to Section 2 for the proper
switch settings for both the IEEE and serial terminators.
3.3 IEEE Address Selection
SW3-1 through SW3-5 select the IEEE bus address of the IEEE peripheral the
Serial488A will be communicating with. These switches set the address of the IEEE
device that will be controlled, not the address of the Serial488A. The address of the
Serial488A is automatically adjusted so that address conflicts will not occur. The
address is selected by simple binary weighting with SW3-1 being the least significant
bit and SW3-5 the most significant. If address 31 (reserved on the IEEE bus) is
selected in the controller mode, address 30 is assigned as the device it will be
communicating with. The following figure shows the IEEE address selection of 10.