MSI-3750 Digital Weight Indicator
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User Guide
Page 107
M E A S U R E M E N T S Y S T E M S I N T E R N A T I O N A L
COMPUTER OPERATION
The MSI-3750 can interface to computers via the RS-232 or RS-485 options. All
functions can be controlled remotely and all setups can be downloaded automati-
cally. The computer can query the scale at any time to get status, weight, or
accumulated totals. In a RS-485 network, multiple scales (up to 255) can be
“daisy-chained” to one or more RS-485 equipped computers for a complete scale
control and data system. Scales can “talk” and “listen” to the master computer
independently, or the master computer can download commands to any or all
scales on the network.
General Protocol
The MSI-3750 responds to ASCII commands that consist of a two letter mne-
monic. Depending on the command, a 1 or 2 digit item selection (sub-code) may
be required. Certain commands require user supplied data. Commands sent from a
host computer can be chained together in any order. Commands are terminated by
another command or by a semicolon (;). It is necessary to end a multiple com-
mand string with the semicolon as a terminator. Variable length numeric data
must be terminated by a semicolon or by another command. Variable length
alphanumeric data must be terminated by a semicolon before adding additional
commands. Commands are case sensitive, only capital letters are used. The 3750
will not accept commands if it is in any setup mode caused by pushing the
SETUP
key.
It is important that the final character sent to the 3750 is a semicolon (;).
“@” COMMANDS UNDER COMPUTER CONTROL
The “@” commands also function under computer control, however they act
differently than standard computer commands. The “@” commands, when
received by the 3750, will cause the immediate transmission of the asked for data
type out the same port. The “;” delimiter is usually not necessary unless the “@”
commands are combined with the standard computer commands. The preferred
way to get data from the 3750 is to use the “CD” command, set up a print string
with all the @ codes desired, then use the “PR” command to cause a data trans-
mission. Once the print string is set up with the desired data, only the PR com-
mand is needed.
Summary of Contents for MSI-3750
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