Analog Devices AN533 Application Notes
AN-533
a
APPLICATION NOTE
One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106 • 781/329-4700 • World Wide Web Site: http://www.analog.com
Applying the 5B Series Backplanes and Mounting Cards
VOLTAGE
I/O
+5V
POWER
CHANNEL
0
Figure 1. 5B01 Functional Block Diagram
INTRODUCTION
The 5B Series includes a number of multichannel
backplanes and mounting cards that provide a complete
signal conditioning solution. Four backplanes currently
available, the 16-channel 5B01 and 5B02 and the 8-channel 5B08 and 5B08-MUX, provide different system configuration options for the user. Models 5B01 and 5B08
I/O signals are independently available, while model
5B02 and 5B08-MUX I/O signals are controlled via an onboard multiplexer providing a bus for input signals and
a separate bus for output signals. With all backplanes,
5B Series modules can be mixed or matched and may be
changed without disturbing field wiring or system
power. The 5B03 and 5B04, one- and two-channel
mounting cards, allow an economical means to handle a
few remote signals. A single-channel mounting card,
AC1360, is available for ease of complete 5B Series
module evaluation.
Both 16-channel backplanes can be mounted in a
19" × 3.5" panel space, such as the rack mount kit, model
AC1393. The 8-channel backplanes can also be mounted
in the AC1393. The one- and two-channel mounting
cards, models 5B03, 5B04 and AC1360, are DIN rail compatible using available hardware. All backplanes and
mounting cards provide individual channel screw terminals for field connections. These connections satisfy all
transducer inputs and process current outputs and provide sensor excitation when necessary. A cold junction
temperature sensor, model AC1361, is supplied on each
channel to accommodate thermocouple modules (5B37
or 5B47). All backplanes and mounting cards require an
external regulated +5 V dc power supply.
CHANNEL
1
CHANNEL
14
CHANNEL
15
MODEL 5B01 BACKPLANE
The 5B01, diagrammed in Figure 1, is a 16-channel backplane that provides single-ended, high level analog
input/output pins on the system connector. It is pin compatible with Analog Devices’ 3B Series applications.
(Note, however, that 5B Series modules provide a ±5 V
output swing rather than the ±10 V swing provided by
3B Series modules.)
Model 5B01 System Connectors
Signal connections between the 5B01 backplane and the
associated measurement and control system are made
at P1 and P2. These connectors are identical electrically.
The redundant connectors may be useful if a 5B01 is
used for both analog input and analog output and the
data acquisition system has separate input and output
connectors. Figure 2 is a diagram of the voltage I/O
provided on the P1 and P2 connectors of the 5B01
backplane.
CH 0
COM
CH 1
CH 2
COM
CH 3
CH 4
COM
CH 5
CH 6
COM
CH 7
SENSE
1
3
5
7
9
11
13
15
17
19
21
23
25
TOP VIEW
NC = NO CONNECT
2
CH 8
4
CH 9
COM
6
CH 10
8
CH 11
10
COM
12
CH 12
14
CH 13
16
COM
18
CH 14
20
CH 15
22
24
COM
26
NC
Figure 2. 5B01 and 5B08 System Connector Pinout
AN-533
FROM
CHANNEL
SELECT
LOGIC
POWER
FROM DAC
+5V
ADDRESS
DECODERS
4
4
TO A/D
16
16
OUTPUT ENABLE
INPUT ENABLE
OUTPUT BUS
INPUT BUS
. . . .
CHANNEL
0
Figure 3. 5B02 Functional Block Diagram
A signal path is provided for each channel and, in addition, a number of grounding pins are present in the connector pinout to provide interchannel shield conductors
in the ribbon cable. In some cases, discussed below, the
ground conductors will not provide an accurate signal
reference, so a SENSE pin is also provided in the pinout.
Several jumper and component options on the backplane provide optimum ground connections for various
circumstances.
Model 5B01 Grounding
Each 5B01 backplane is factory configured with Jumpers
W1, W3 and W4 installed. Jumper W1 grounds the
shield wires in the ribbon cable (Pins 3, 6, 12, 15, 18, 21
and 24) at the 5B01 backplane. This will usually be the
primary ground connection between the 5B01 and the
measurement system. This connection is required if output modules will be used on the backplane. It is also required if there is no high impedance sense input (input
Low of a differential or pseudo-differential system)
available on the measurement system. Jumper W3 connects the sense input, if available, to Pin 25 so that the
5B01’s ground is read. It can be left in place at all times.
Jumper W4 connects +5 V dc power common to input/
output common (backplane measurement ground). A
connection between power common and input/output
common is important for the 5B Series modules to function properly; however, if this connection is made elsewhere in your system (the best place is usually near the
A/D or D/A converters), W4 should be cut, since a
ground loop could result.
Model 5B01 Interchannel Bridge Jumpers
The 5B01 gives the user the capability of directing the
voltage output of any input module to an adjacent output module (e.g., Model 5B39) simply by placing a
jumper between the pins of the two modules (input to
channel n, output from channel n + 1). This feature can
be used to provide an isolated current output from an
isolated input module, giving two levels of 1500 V rms
isolation. Model AC1344 provides ten jumpers.
CHANNEL
1
CHANNEL
14
CHANNEL
15
MODEL 5B02 BACKPLANE
The 5B02, diagrammed in Figure 3, is a 16-channel backplane. It incorporates input and output buses that take
advantage of the internal series output switches in the
input modules and the track-and-hold in the output
module. Designers integrating the 5B02 into a measurement and control system do not need external multiplexers and can use a single digital-to-analog converter
to serve numerous output channels. Digital outputs
from the host data acquisition system are used to address the 5B Series modules and designate inputs and
outputs. Only one analog input, one analog output, and
a number of digital outputs are required to address up to
64 analog input/output channels.
Model 5B02 System Connectors
Signal connections between the 5B02 backplane and the
associated measurement or control system are made at
P1. The pinout of this connector is illustrated in Figure 4.
1
V
READ
V
3
WRITE
I/O COM
READ
(INPUT)
ADDRESS
WRITE
(OUTPUT)
ADDRESS
READ ENB (0)
IS THE ANALOG OUTPUT OF INPUT MODULES
V
READ
V
IS THE ANALOG INPUT OF OUTPUT MODULES
WRITE
MATING CONNECTOR AMP PN746290-6 OR EQUIVALENT
LSB
BIT 3
BIT 5
LSB
BIT 3
BIT 5
NC
NC
D COM
5
7
9
11
13
15
17
19
21
23
25
TOP VIEW
NC = NO CONNECT
2
I/O COM
4
SNS LO
I/O COM
6
BIT 2
8
BIT 4
10
MSB
12
BIT 2
14
BIT 4
16
MSB
18
WRITE ENB (0)
20
RESERVED
22
24
NC
26
D COM
READ
(INPUT)
ADDRESS
WRITE
(OUTPUT)
ADDRESS
Figure 4. 5B02 System Connector Pinout
–2–
AN-533
SH
1
2
3
4
5
SH
6
7
8
9
10
One signal path is provided for inputs and one for outputs. Input and output modules are independently addressed by two sets of six address pins and an enable
pin. In addition, a number of grounded pins are present
in the connector pinout to provide shield conductors in
the ribbon cable. In some cases, discussed below, the
ground conductors will not provide an accurate signal
reference, so a SENSE pin is also provided in the pinout.
ignored. Moving the jumpers to any other position in the
two blocks enables decoding of the full six address bits;
the exact position of the jumper determines address
position for the backplane as shown in Table I. To use
multiple backplanes in this manner, connect the corresponding I/O connector pins of each backplane in
parallel. CAB-01 is a ribbon cable with three 26-pin con-
nectors designed for this purpose.
Several jumper and component options in the backplane provide optimum ground connections for various
circumstances.
Model 5B02 Grounding
Each 5B02 backplane is factory configured with Jumpers
W1, W2 and W4 installed. Jumper W1 grounds the
shield wires in the ribbon cable (Pins 2, 5 and 6) at the
5B02 backplane. This will usually be the primary ground
connection between the 5B02 and the measurement
system. This connection is required if output modules
will be used on the backplane. It is also required if there
Figure 5. 5B02 Address Selection Pins Shown with
Factory Default Jumpers
is no high impedance sense input (input low of a differential or pseudo-differential system) available on the
measurement system. Jumper W2 connects the sense
input, if available, to Pin 25 so that the 5B02’s ground is
read. It can be left in place at all times. Jumper W4 connects +5 V dc power common to input/output common
(backplane measurement ground). A connection between power common and input/output common is im-
Input Jumper Output Jumper Address Range
2 7 48–63
3 8 32–47
4 9 16–31
5 10 0–15
Table I. 5B02 Address Selection Jumpers
portant for the 5B Series modules to function properly;
however, if this connection is made elsewhere in your
system (the best place is usually near the A/D or D/A
converters), W4 should be cut since a ground loop could
result.
Model 5B02 Address Selection Jumpers
The 5B02 backplane can hold 16 modules in any combination of inputs or outputs. Address decoders on the
backplane (separate decoders are provided for inputs
and outputs) determine which module is read (inputs) or
driven (outputs). To permit system expansion, up to four
backplanes can be daisy-chained on the system I/O ribbon cable for a total of 64 channels. Jumpers on each
backplane (labeled SH1-5 and SH6-10) determine the
block of 16 addresses assigned to each backplane. Input
(read) and output (write) addressing are completely independent; in all cases, Jumpers 1–5 control inputs and
6–10 control outputs. Independent addressing might be
used, for example, to update output modules without
interrupting the monitoring of input modules.
Backplanes are factory configured with jumpers at Positions 1 and 6; Figure 5 shows the address jumpers in the
MODEL 5B08 BACKPLANE
Model 5B08 System Connectors
Signal connections between the 5B08 and the associ-
ated measurement and control system are made with
two identical 26-pin connectors (P1 and P2), similar to
the 16-channel model 5B01 backplane. Reference to
these connectors is electrically identical and may be
useful if a 5B08 is used for both analog input and analog
output and the data acquisition system has separate in-
put or output connectors. Figure 2, shown with model
5B01, illustrates the pin assignments for P1 and P2.
The I/O connectors provide a signal path for each chan-
nel and, in addition, a number of grounding pins are
available to provide interchannel shield conductors in
the ribbon cable. In some cases, discussed below, the
ground conductors will not provide an accurate signal
reference, so a SENSE pin is also provided in the con-
nectors. Several jumper and component options on the
5B08 provide optimum ground connections for various
applications. These are discussed in the following
sections.
factory configured positions. This sets up the backplane
as a stand-alone 16-channel system; the two highestorder address bits in the read and write addresses are
–3–
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