SATO MB400i Operator's Manual page 57

Special Settings
WARNING: Never connect or disconnect interface
cables (or use a switch box) with power applied to
either the host or the printer. This may cause
damage to the interface circuitry in the printer/host
and is not covered by warranty.
Note: Some hosts monitor the Request-To-Send
(RTS) signal (pin 4 of 25) to determine if the printer
is ready to receive data. Since the printer does not
generate this signal, the RTS line must be held true
(high) in order to allow communication. Perform
this by connecting the RTS pin to the Clear-To-
Send (CTS) signal (pin 5 of 25).
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