ASEA AC100LC-3, Operation Manual

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AC90LC-3, AC100LC-3, and AC125LC-3 Operations Manual....
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6.5 REMOTE COMMUNICATIONS, cont.
6.5.1 RS-232C/SCPI
The RS-232C serial port is located at the base of the Control PCB box just above the heat exchanger.
The RS-232C TxD signal originating in the converter is approxi15V when “High” and -15V
when “Low.” The RS-232C GND (ground) wire is connected to the low voltage DC common of the
converter power supply system, which is normally also connected to the chassis-ground of the
converter. When the Metering Isolation Option is installed in the converter, the link to the chassis
ground is removed.
The RS-232C serial port is a DE9S (female, 9-pin D-subminiature connector). The pinout of the
connector is standard for an RS-232C DCE. Figure 10 below demonstrates connection from a DCE
to a DTE. Use of a shielded, jacketed, four-wire (two twisted pairs), color-coded cable for each
converter in the system is required.
FIGURE 10 RS-232C PINOUT
It is strongly recommended that an RS-232C optical isolation be included in any RS-232C/SCPI
protocol integration to avoid the creation of ground-loops and ground-fault paths through the remote
communication port; such isolation is not included with the standard product.