American Magnetics 187 Self-Compensating Liquid Level Controller - Manual (Page 50)

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Remote Interface Reference
IEEE-488 Configuration
transmission. The Model 187 can accept , , , or
, or a semicolon ( ; ) as termination characters from an external
computer.
4.3.3 Flow Control Modes
The operator may select between two flow control modes for data transfers
between the host device and the Model 187:
W None: Data is sent and received over the interface with no flow
control. When using this mode, avoid sending more than 64
characters without stopping or reading a response.
W Software: Also referred to as XON/XOFF. Software handshaking
uses special embedded characters in the data stream to control the
flow. If the Model 187 is asked to return data, it continues data
output until the XOFF character (13 Hex) is received. Once an XOFF
character is received, an XON character (11 Hex) is required for data
transmission to continue.
The Model 187 also sends XON/XOFF when its internal serial port
buffer reaches a “high-water” mark. The host device should suspend
transmission on receipt of an XOFF character from the Model 187,
and resume when an XON character is received.
Note
The XON/XOFF flow control should not be used as a substitute for
command handshaking as documented in paragraph 4.2.5.
XON/XOFF characters are not generated in the case of “input
overflow” errors (error number -303).
4.4 IEEE-488 Configuration
The Model 187 allows the primary IEEE-488 address of the Model 187 to
be configured by the user. See the Comm Menu description in paragraph
3.3.10 on page 22 for an illustration of the menu provided for configuring
the Model 187 IEEE-488 address.
4.4.1 Termination Characters
All commands are transmitted and received as ASCII values and are case
insensitive. The Model 187 always transmits with EOI as the
termination for return data. The Model 187 can accept , , or
with EOI as termination characters from an external IEEE-488
interface. More than one command may be sent before a terminator if each
command is separated with a semicolon ( ; ).