DH Instruments MOLBOX ANALOG CIRCUIT, User Manual

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1. INTRODUCTION
Page 1 © 1997-2002 DH Instruments, Inc.
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1.1 PRODUCT OVERVIEW
The purpose of this software is to calibrate the MFC analog control circuit in molbox1™. There are three
separate lines that are individually calibrated by the software. First there is the set line that is used to set
MFC set points. Then there are two input lines, the sense and the measure. The sense line is used
to readjust the set value to match itself and the measure line is used to read the output of the MFC.
The measure line is the most important of the three, even if the set point and sense point are out of
tolerance, the measure line will still allow an accurate calibration if it is within tolerance. In current (mA)
mode there is no sense line so N/A appears in all sense fields while in current mode.
1.2 GETTING STARTED
Make sure that your PC has the following minimum requirements: Windows
®
3.0, 4 MB of RAM and 1 MB of
hard disk space. To install the software, insert the moltools installation disk and run the setup utility. This can
be done in Windows by going to the File Menu, selecting Run and typing “A:\SETUP”, or in Windows 95
by pressing Start and choosing Run then typing “A:\SETUP” (where ‘A’ represents the drive that the
installation disk is located). This utility will install the molbox Analog Calibration program and all of its
associated files into the moltools directory and create a program group in Windows named molbox
moltools.
Before attempting to run the Analog Calibration program, be sure that the molbox COM1 port is
connected to one of the communications ports of the host PC with a standard RS232 cable. This allows
the program to auto-detect molbox and the serial communications setup is skipped. To run the program
double click the Analog Calibration Icon. In most cases, if everything is properly attached, the software
will auto-detect molbox and the calibration form will follow. The exceptions are when the current settings
of the molbox COM1 port are not Even parity, 1 Stop bit, 7 Data bits, and Baud rates of 2 400 or above.
In these cases, you will have to manually set up the communications. It is also possible that a general
communications error will occur or some other unexpected problem that has not been mentioned. If so,
choose the Communications menu option and select the proper settings from the Serial Communications
Form shown at the end of this document in the Forms/Diagrams section. If you cannot determine the
current settings of molbox, use the following procedure from the molbox keypad:
Press [ESC] until you return to the main menu if you are NOT already there.
Select <0 Special> , followed by <5 Internal> and <2 Remote> . Old style molbox1 users should
select: <3 Special> , <8 Internal> , <2 Remote> , <1 com1> .
If the molbox has an IEEE 488 option, select COM1 after selecting Remote in the previous step.
Either change the baud rate with the number keys and select [ENTER] , or bypass it to view the next
parameter by pressing enter.
Repeat Step for Parity, Word Length and Stop Bits, and terminating characters.
Select the proper configuration on the Serial Communications Form and press [OK] .