7B Series Backplanes and
Mounting Cards
General
Description
To complement the 7B Series signal
conditioners, Analog Devices offers a variety of
multi-channel backplanes and a single-channel DIN rail
mount mounting card, designed for 7B modules. Backplanes
are presently available in 4-, 8- and 16-channel
configurations (model numbers 7BP04-1, 7BP08-1 and
7BP16-1, respectively). The 7BP04-1, 7BP08-1 and 7BP16-1
backplanes may be mounted in a 19" x 3.5" panel space
via rack-mount hardware kit (Model AC1363) available
from Analog Devices. The backplanes are also designed to
mount on a flat surface with standoffs provided with
each backplane - mounting screws are provided with the
AC1363
rack-mount kit. For smaller applications, the single
channel mounting card, model AC1387, is provided with
DIN rail mounting hardware. |
|
Models 7BP08-1
and 7BP04-1
|
|
Model
7BP16-1 |
Field and System
Connections
Field connections for transducers/signal inputs, 2-wire
transmitter loop power inputs and current outputs, are made
through a three-screw terminal block - refer to the Field
Connection figures shown in each model section. On all
backplanes, the interface to the user's system is accomplished
by a standard 25-pin D-type connector. Two identical 25-pin
male connectors located on the backplanes provide a means of
optionally having separate input and output connections when
input and output modules are being used on the same backplane.
Figure 1 illustrates the functional block diagram for the
Model 7BP16-1 backplane, indicating the terminal designations
for the power supply and field connectors. On the AC1387
mounting card, system interface is made with screw terminal
connectors. |
Figure 1. Functional
Block Diagram, Model 7BP16-1 |
Application
Flexibility
To insure the reliability of the module's electrical
connection to the backplane, gold-plated sockets are provided
on each channel. To accommodate thermocouple signal inputs, a
miniature cold junction compensation (CJC) thermistor is
mounted under the input terminal block of each backplane and
mounting card channel. The thermistors are embedded in the
circuitry under the I/O screw terminal blocks and are not
visible on the backplane or mounting card. For users
constructing their own backplane or mounting card, the
thermistor is commercially available from the manufacturer,
Betatherm Corp., part number 100K6A1. Refer to the 7B Series
User manual for additional information. In addition to the CJC
temperature sensor for each input channel on the backplanes, a
pair of pin sockets permits installation of the AC1391
current sensing resistor used with the Models 7B30 and 7B33 voltage input
modules for process current inputs. (Not available on Model
AC1387). |
Model
AC1387 |
Powering
Flexibility
The 7B Series are powered by a single +24 V dc power
supply. Linear supplies, whether regulated or unregulated, are
recommended. Most modules operate between +14 Vdc and +35 V
dc. Four screw terminals are provided on the backplanes to
allow several ways of supplying power to the 7B Series
backplane. Figure 2 defines the terminals and illustrates how
a redundant power supply scheme can be implemented. As
illustrated, three power supply terminals are provided for
connecting the high side of the power supply to the backplane.
This allows three different connection schemes.
1. A single power supply can be connected to either V+A or
V+B terminals. 2. Redundant supplies are connected to V+A
and V+B terminals. 3. A low voltage power supply of +14 V
dc or +15 Vdc can be connected to the V+ terminal, thereby
avoiding the voltage drop across the diodes that are in series
with the V+A and V+B terminals.
The backplane diodes serve two purposes. One is to provide
the means of switching redundant power supplies; the other is
to protect 7B Series modules from a reverse polarity
connection. A single LED on each backplane indicates the power
ON status. |
Features
- Mix and Match 7B Series I/O Module Capability
- CE Certified
- 1500 V rms Channel/Channel and Input/Output
Isolation
- Three Backplanes; 4-, 8-, 16-channel capacity
- Single Channel, DIN-Rail Mounting Card
- Redundant Power Supply Connectors on all
Backplanes
- Dual System Connectors on all Backplanes
- -25°C to +85°C Temperature Range
- Single Threaded Insert for Module Hold Down
|
Figure 2. Wiring
Diagram of Backplane Power Input Terminals - Note:
Diodes are provided on the
backplane. |
|
7B Series
Backplane Specifications (typical @
+25°C and Vs = +5 V dc)
Description |
7BP04-1 |
7BP08-1 |
7BP16-1 |
Analog I/O Channels |
4 |
8 |
16 |
Interface |
Analog Sensor Input/Output |
1500 V rms, maximum |
* |
* |
Connector Type |
3-Screw Terminals |
* |
* |
System Connectors |
2 |
* |
* |
Connector Type |
25-pin D Connector |
* |
* |
Cold Junction Temperature
Sensor |
Number provided on backplane |
4 |
8 |
16 |
Type |
Thermistor |
* |
* |
Accuracy over +5°C to +45°C ambient |
±1.0°C, maximum |
* |
* |
Provision For Mounting AC1391
Resistors |
Yes |
* |
* |
Backplane Mounting
Standoffs1 |
4 |
5 |
7 |
Isolation |
Input-to-Output, Channel-to-Channel |
1500 V rms, max. continuous |
* |
* |
Input Transient Protection |
ANSI/IEEE C37.90.1-1989 |
* |
* |
Power
Supply |
Voltage: Operating |
+14 V dc to +35 V dc |
* |
* |
Voltage: Max. Safe Limit with
module |
Depends on 7B Module2 |
* |
* |
Reverse Voltage Protection |
Yes3 |
* |
* |
Current |
20 mA4 |
* |
* |
Fuse |
5 ampere, slow-blow Littelfuse®
251.005 |
* |
* |
Mechanical Dimensions |
3.47" x 6.30" (88.14 mm x 160.02
mm) |
3.47" x 10.0" (88.14 mm x 254
mm) |
3.47" x 17.4" (88.14 mm x 441.9
mm) |
Environmental |
Temperature Range |
Rated Performance |
-25°C to +85°C |
* |
* |
Operating |
-25°C to +85°C |
* |
* |
Storage |
-40°C to +85°C |
* |
* |
Relative Humidity |
0 to 95% @ +60°C noncondensing |
* |
* |
* Specifications same as model 7BP04-1.
1 Mounting hardware is provided
with the Rack-Mount Kit, Model AC1363.
2Maximum supply voltage rating for
Models 7B21 and 7B22 is +29 V dc; +35
V dc for all others. 3Reverse
voltage polarity protection is provided when using either the V+A or
V+B power input terminals. 4Current drawn by LED ON light. Specifications subject to change without
notice.
|