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TTI-7 Iss.02 – 06/11
If a 3-wire (TXD, RXD, GND) connection is to be used, connect RTS to CTS at the instrument end. But take care;
sending characters too quickly to the instrument could cause its receiver buffer (4 characters) to overflow and
subsequent characters may be lost. Always use a time delay between transmitted characters, or better still, use the
full 5-wire connection for reliable hardware handshaking of each character.
It is recommended that Isotech cable be used for connecting the instrument to a PC. This has the 5-wire connection
and will maintain EMC integrity.
Front Panel Set Up
Press OPT on the front panel and select Rem I/F. A further menu will now allow the selection of Talk Only Mode and
Baud Rate.
Talk Only Mode
Select ON to force the Talk Only Mode. In this mode the interface will ignore all incoming interface commands and
the instrument will remain in LOCAL control mode. The result of each temperature measurement is sent to the
interface output with the resolution and units as per the main display. See section 3.1 for output data format.
This mode is useful for sending results directly to a printer without the need for a PC.
Baud Rate
On selecting Baud Rate, the current setting is displayed. This defaults to 9600 following an instrument reset, and is
the usual setting on shipment. If this is acceptable press “OK”.
To change the value, press “Chg” and enter the new rate required.
Valid rates are 75, 110, 150, 300, 600, 1200, 2400, 4800, 9600, 19200 Baud.
These set the Baud rate for both transmit and receive.
The data word format is fixed at:
Start bit:
1
Data word length:
8 bits
Parity checking:
None
Stop bit:
1
Software handshaking using XON/XOFF is not implemented
.
Communicating
In order to communicate with the instrument using RS-232, the command “SYSTem:REMote” must first be sent (see
“RS-232 Interface Commands”).
