Impulse SCMPB01 - Manual (Page 11)

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Isolated Analog Signal Conditioning Products SCM5B
SCMPB06
8-Position Analog I/O Backpanel, Multiplexed
Description
The SCMPB06 backpanel (Figure 14) can accept up to eight SCM5B modules
in any combination. It can be mounted on the SCMXRK-002 19-inch metal rack.
The SCMPB06 has two analog buses; one for analog input and one for analog
output. This two-bus configuration takes advantage of the switch controlled
outputs on the input modules and the track-and-hold inputs on the output
modules. A temperature sensor is mounted on each channel to provide cold
junction compensation for thermocouple input modules (See Figure 15 for
schematic). Field connections are terminated with four screw terminals at each
module site. Up to eight SCMPB06 backpanels may be daisy-chained. Use
SCMXCA004-XX cable for daisy chaining and connecting to host computer.
Jumpers on the SCMPB06 permit user selection of low (i.e. channels 0-7) or
high (i.e. channels 8-15) addresses.
Ordering Information
Part Number Description
SCMPB06 Standard 8-channel backpanel.
SCMPB06-1 SCMPB06 without cold junction compensation circuits. Use
when cost savings is desired and thermocouple input modules
SCM5B37 and SCM5B47 will not be used.
SCMPB06-2 SCMPB06 with DIN rail mounting option. The backpanel is
mounted on a piece of anodized aluminum, which is captured
by the SCMXBEFE DIN rail mounting elements. The
backpanel is shipped fully assembled.
SCMPB06-3 SCMPB06-1 with DIN rail mounting option. See SCMPB06
and SCMPB06-2 for details.
Figure 14: SCMPB06 Analog I/O Backpanel
Electrical
Address Selection
Module read and write addresses may be selected as low (channels 0-7) or
high (channels 8-15) using the four sets of 3 position jumpers labeled J5 through
J8. Place a jumper over the two pins furthest from the field I/O termination blocks
on all four sets to select a low address (factory configuration) or over the two
pins closest to the field I/O termination blocks on all four sets to select a high
address.
The SCMPB06 backpanel has address decoding circuitry to allow multiplexing
any combination of up to 8 input or output modules. Capability is also provided
in the address decode circuitry to expand the system to 64 channels (eight
SCMPB06 backpanels) of multiplexed input or output. Jumpers select which set
of 16 addresses are assigned to a particular backpanel. The Read Address
group assigns a set of 16 addresses for input modules, and the Write Address
group assigns a set of 16 addresses for output modules. The table below shows
the correlation of jumper position to address range. Refer to page 51 for
additional notes on the P1 connector, power requirements, fusing, and
grounding issues.
Specifications
Operating Temperature –40°C to +85°C
ATEX Group II, Category 3 –20°C to +40°C
Relative Humidity 95% non-condensing
Interface Connector:
Field high density screw clamp, 14 AWG max
System 26-pin, male header connector
Address Input Logic Levels:
Max Logic “0” 0.8V
Min Logic “1” 2.0V
I
I
Input Current, “0” or “1” 0.1µA max at 25°C
1.0µA max –25°C to +85°C
RD EN\ or WR EN\ Signal Delay
from Connector P1 to Channels 0-7
Standalone (address 0-7) 51ns at 25°C, 64ns at –25°C to +85°C
Expanded (address 8-63) 100ns at 25°C, 126ns at –25°C to +85°C