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User's Guide
44
Digital Communication Interface
If supplied with the option, the bath is capable of communicating with and being
controlled by other equipment through the digital interface. Two types of digital
interface are available — the RS-232 serial interface and the IEEE-488 GPIB
interface.
With a digital interface the bath may be connected to a computer or other
equipment. This allows the user to set the bath temperature, monitor the
temperature, and access any of the other controller functions, all using remote
communications equipment. In addition the heater power setting and cooling
capacity may be controlled using the interface. To enable the heater to be
switched to high using the interface the “HEATER” switch must be set to the
“LOW” position. The cooling power switch must be set to OFF to enable remote
control.
Serial Communications
The bath may be installed with an RS-232 serial interface that allows serial digital
communications over fairly long distances. With the serial interface the user may
access any of the functions, parameters and settings discussed in the
Interface
Commands
section with the exception of the BAUD rate setting. The serial
interface uses 8 data bits, 1 stop bit, and no parity.
Wiring
The serial communications cable attaches to the bath through the DB-9
connector at the back of the instrument. Figure 9 shows the pin-out of this
connector and suggested cable wiring. To eliminate noise, the serial cable should
be shielded with low resistance between the connector (DB-9) and the shield.
figure 9.eps
Figure 9. Serial Cable Wiring