MKS 670B - Environmental Specifications; Electrical Specifications

Cha
p
ter Seven: IEEE-488 Communications O
p
tion MKS Device De
p
endent Messa
g
es
125
Example 2: How To Read the Input Signals on the I/O Connector
To perform this diagnostic test you will need to configure each input so you know the bit value
of the connector. The I/O connector has 16 inputs. Table 26, page 101, lists the input bit
number assignments and their bit values. A value of 65535 indicates that all the inputs are high.
To determine the connector value, add the bit values of the bits you wish to pull low, and
subtract that value from 65535.
1. Connect bit 7 (I/O pin 24) and bit 15 (I/O pin 10) to digital ground (I/O pin 4) to pull the
inputs low.
2. To determine the value of the inputs read by the 670 instrument, issue the query:
:cont:in?
3. The 670 instrument will respond with:
40987 <CR LF>
To determine whether bits 7 and 15 are low, subtract the value of each bit from the total
value of the connector:
65535 - (64 + 16384) = 49087
Connector value
when all bits are hi
g
h
Value of bit 7
Value of bit 15
Value returned by
the 670 instrument
The value returned by the 670 instrument indicates that bits 7 and 15 are low.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com