Fluke Biomedical 4000M+ - Manual (Page 36)

Victoreen 4000M+
Operators Manual
B-2
Set Up for Exposure (S and O)
There are two commands used to set up for an exposure. The command to instruct the 4000M+ to set up
for an exposure from a tungsten target tube is the character S. The command to instruct the 4000M+ to
set up for an exposure from a molybdenum target tube is the character O.
Table B-1. Model 4000M+ Filter Settings
No. Sent Filter Setting
1
2
3
4
5 27-42 (21-50 for Mo/Mo)
35-60
50-85
70-120
100-155
Table B-2. Status Bit Description
Bit Meaning
0
1
2
3
4
5
Ion chamber integrator offset too high.
Channel A offset too high.
Channel B offset too high.
Ion chamber integrator failure.
Channel A amplifier failure.
Channel B amplifier failure.
When the 4000M+ receives either of these characters, it makes preparations for an exposure. The
4000M+ will not verify proper filter wheel setting (this is up to the PC), nor will it ask for a technique. It will
simply make offset measurements and then proceed with the exposure. The 4000M+ will take slightly
more than one second to make these preparations and then respond by sending an integer value (0
through 63) to the PC (followed by <CR><LF>). This integer represents a status byte. A zero value
indicates successful preparation for exposure. A non-zero value can be broken down into individual bits
and interpreted as listed in Table B-2.
For example, if the 4000M+ returned the value 9 (001001 binary), it would be interpreted as: Ion chamber
integrator offset too high and Ion chamber integrator failure
.
Following is a sample program:
5 REM SET UP FOR EXPOSURE AND CHECK FOR ERROR.
1. PINT #1, “S”;
20 INPUT #1, ER
30 IF ER=0 THEN PRINT “MAKE EXPOSURE.”
40 IF (ER AND 1) <> 0 THEN PRINT “ION CHAMBER OFFSET HIGH”
50 IF (ER AND 2) <> 0 THEN PRINT “CHANNEL A OFFSET HIGH”
60 IF (ER AND 4) <> 0 THEN PRINT “CHANNEL B OFFSET HIGH”
70 IF (ER AND 8) <> 0 THEN PRINT “ION CHAMBER FAILURE”
80 IF (ER AND 16) <> 0 THEN PRINT “CHANNEL A FAILURE”
90 IF (ER AND 32) <> 0 THEN PRINT “CHANNEL B FAILURE”
The procedure is identical for molybdenum anode mammography machines except that an O is sent
instead of an S.
It is the responsibility of the computer program to be sure that the 4000M+ filter wheel is set on the lowest
range.