The DS1821 Programmer uses a BasicX BX24 processor and may be purchased as an assembled unit. The complete package includes a programmed BX24, voltage regulators, a serial cable with a female DB9 connector to interface with a PC COM Port and a wall power unit, all assembled on circuit board. One DS1821 in a PR35 package is provided with the package. Additional DS1821s may be purcahsed for $4.50 each.
A PC running HyperTerm or an equivalent terminal emulator is used to communicate with the BX24. The settings are Direct Connection, 19200 8N1, no flow control.
The three terminal DS1821 to be programmed is inserted in the three terminal connector and the user uses a menu driven program on the BX24 to display the current programmed settings, to set new values of the TH and TL trip points and the polarity of the active alarm state, to display these proposed settings, to save the settings to the DS1821 and to measure the temperature. The user may Quit and insert another DS1821 to be programmed.
A more complete description appears here. However, in using this assembled package, it is not neccessary to understand the operation of the BX24.