Measurement Computing Micro 488/EX rev.2.1 - Manual (Page 9)

Section 1 Introduction
1.1
Introduction
1.1 Description
The Micro488/EX Stand Alone Bus Controller converts a host RS-232 or RS-422
computer into an IEEE 488 bus talker, listener and controller. The Micro488/EX
provides full IEEE 488-1978 bus implementation including advance capabilities such
as PASS CONTROL, RECEIVE CONTROL, PARALLEL POLL, SERIAL POLL and
SECONDARY ADDRESSING. The device may be located several hundred feet from
the host and may control as many as fourteen 488 bus instruments. In the non-
controller mode the Micro488/EX converts the host into a bus peripheral for data
processing and mass storage. The Micro488/EX interprets simple high level commands
sent from the computer's serial port and performs the necessary, and usually complex,
bus control and handshaking. The commands and protocol are similar to those used by
the Hewlett Packard HP-85 computer.
A unique feature of the Micro488/EX is its macro capability. Macros are mini-
program sequences that can be used to collect data for later recall by the serial host
computer. Up to 100 different macros can be defined and maintained in non-volatile
memory. The data collected by macros can be immediately sent to the serial host or
placed into a non-volatile log buffer for later recall. The data collected can also be date
and time stamped using the Micro488/EX's internal time-day-date clock. Macros can
also be executed as a result of some external event, such as SRQs or Errors.
Additional features provide a transparent IEEE to serial converter and a serial to
IEEE pass-thru controller.
As a serial to IEEE 488 converter, the Micro488/EX receives data from a serial
host then automatically performs the bus sequences necessary to send this data to the
IEEE 488 device. If desired, data can be requested from the IEEE 488 device and
returned to the host.
As an IEEE 488 to serial converter, the Micro488/EX is a peripheral to an IEEE
488 controller. Data received from the controller is sent to the serial device and data
received from the serial device is buffered for transmission to the IEEE 488 controller.
The Micro488/EX can inform the host, by the serial poll status byte, that it has received
data from the serial device.