Special Handling Of Static-Sensitive Devices; Principles Of Operation; Block Diagram; Figure 4-5 Block Diagram - Keithley 7017 Instruction Manual

Servicing
4.4 Special handling of static-sensitive
devices
CMOS and other high-impedance devices are subject to pos-
sible static discharge damage because of the high-impedance
levels involved. When handling such devices, observe the
following precautions.
To prevent damage, assume all parts are
static-sensitive.
• Such devices should be transported and handled only in
containers specially designed to prevent or dissipate
static build-up. Typically, these devices will be received
in anti-static containers made of plastic or foam.
• Keep these parts in their original containers until ready
for installation or use.
• Remove the devices from their protective containers
only at a properly grounded workstation. Also, ground
yourself with an appropriate wrist strap while working
with these devices.
From
Mainframe
Figure 4-5

Block diagram

4-8
NOTE
Memory
To
Mainframe
U103
+6V
Relay
Drivers
Data
Clock U101,
U102
Strobe
Power Up/Down
Safeguard
• Handle the devices only by the body; do not touch the
pins or terminals.
• Any printed circuit board into which the device is to be
inserted must first be grounded to the bench or table.
• Use only anti-static type de-soldering tools and
grounded-tip soldering irons.
4.5

Principles of operation

The following paragraphs discuss the basic Model 7017 op-
erating principles that can be used as an aid in troubleshoot-
ing the card. The schematic diagram of the card is located at
the end of Section 5.
4.5.1 Block diagram
Figure 4-5 shows a simplified block diagram of the Model
7017. Key sections include the relay data control circuits, the
relay driver ICs, the relays, and the card configuration mem-
ory. These elements are discussed in the following para-
graphs.
Out A
MUX
1
A
2
K101-K106
3
4
Out B
MUX
5
B
6
K107-K112
7
8
Multiplexer A
Inputs
Multiplexer B
Inputs