Impulse SCMXIF - Manual (Page 6)

Isolated Process Control Signal Conditioning Products SCM7B
For information call 800-444-7644 92
SCM7BP04(-DIN)/SCM7BP08(-DIN)/SCM7BP16(-DIN)
Backpanels
Description
The SCM7BP04, SCM7BP08, and SCM7BP16 (see Figures 10-13) are 4, 8,
& 16 channel backpanels that can accept any of the SCM7B analog modules.
All three of these backpanels can either be rack mounted using Dataforth’s 19-
inch rack P/N SCMXRK-002 (using the provided 3mm screws), or directly
mounted to a surface using #6 or smaller screws. The SCM7BP04-DIN,
SCM7BP08-DIN, and SCM7BP16-DIN are identical to their standoff counter-
parts but with DIN rail mounting brackets attached instead of standoffs. These
brackets allow the backpanels to be mounted on either EN 50022-35 x 7.5 (35
x 15) or EN 50035-G32 type DIN rails.
System Side - Power
Using the “V+” power supply input, the power supply voltage can be as little as
+14VDC. If +15VDC is available, it is recommended that the supply be
connected between the “V+A” or “V+B” connections and “COM”; this will protect
the modules against accidental supply reversal. Using both these connections
with two power supplies enables redundant power supply operation. It is also
recommended that a diode transient absorber be installed to reduce power
supply transient events from degrading system performance. An “accessory”
location, between the supply and common lines, is provided for this purpose.
A system side grounding #10-32 stud is also provided for use if desired.
All backpanels are fused according to channel count, allowing 1/4 Amp
per channel.
Specifications
Operating Temperature –40°C to +85°C
ATEX Group II, Category 3 –20°C to +40°C
Relative Humidity 90%
Interface Connector:
Field high density screw clamp, 10-24 AWG
System 2 DB25 (male) connectors with 4-40 screwlocks
System Side - Signal
Two system interface DB25 connectors are used, to enable using both input and
output modules simultaneously, or to route the signal from an input module
backplane to an output module backplane. These backpanels use either the
SCM7BXCA01 (DB25 to 26-pin adapter cable) and SCMXCA004-XX (26-pin
to 26-pin interface cable), or the SCM7BXCA02 (DB25 to DB25 interface cable),
depending on system requirements.
Field Side - Signal
On the field side a temperature sensor is mounted underneath the field side
terminal block to provide cold junction compensation for thermocouple modules,
and a current-to-voltage conversion resistor (P/N SCM7BXR1) socket location
is provided (supplied with SCM7B33 modules) for each channel. Field
connections are terminated with three screw terminals.
Figure 10: SCM7BP04(-DIN) Dimensions