Service Information
6-14
4. Any printed circuit board into which the device is to be
inserted must first be grounded to the bench or table.
5. Use only anti-static type de-soldering tools and
grounded-tip soldering irons.
Principles of operation
The following paragraphs discuss the basic operating princi-
ples for the Model 7021 and can be used as an aid in trouble-
shooting the card. Schematic drawings 7021-106 and 7021-
172 are located in Section 7.
Block diagram
Figure 6-9 shows a simplified block diagram of the Model
7021. Key elements include the ROM, which contains card
ID and configuration information, multiplexer relay drivers
and relays, and digital I/O output channel drivers and digital
I/O input channel registers. These various elements are dis-
cussed in the following paragraphs.
Figure 6-9
Model 7021 block diagram
To Mainframe
OUTCLOCK
OUTDATA
STROBE
ENABLE
Relay
Drivers
U106-
U109
Relay
Channels
1-30
User
connections
IDCLK
IDDATA
ROM
U110
+3.5V (Steady State)
+5.7 (
≈
100 msec during
relay actuation)
Relay
Power
Control
Q100, Q101
U114, U115
+6V, +15V
To/From
Mainframe
To Mainframe
OUTCLOCK
OUTDATA
STROBE
ENABLE
Output
Channel
Drivers
U105
and
U106
Output
Channels
31-40
From
Mainframe
INDATA
INCLOCK
STROBE
ENABLE
Input
Channel
Registers
U101
and
U102
In 1
In 2
In 10
User
connections
Artisan Scientific - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisan-scientific.com
Summary of Contents for 7021
Page 86: ...Artisan Scientific Quality Instrumentation Guaranteed 888 88 SOURCE www artisan scientific com...
Page 87: ...Artisan Scientific Quality Instrumentation Guaranteed 888 88 SOURCE www artisan scientific com...
Page 88: ...Artisan Scientific Quality Instrumentation Guaranteed 888 88 SOURCE www artisan scientific com...
Page 89: ...Artisan Scientific Quality Instrumentation Guaranteed 888 88 SOURCE www artisan scientific com...
Page 90: ...Artisan Scientific Quality Instrumentation Guaranteed 888 88 SOURCE www artisan scientific com...