Instruction manual

Instruction Manual
760006-A
September 2001
Rosemount Analytical Inc. A Division of Emerson Process Management Description and Specifications 1-19
Model NGA 2000 Platform
b. Analog Functions And I/O Connections
The I/O Modules that include analog func-
tion provide seven relay contacts (contacts
are rated 24 VDC at 1 Ampere resistive)
outputs [three single-pole, double-throw
(SPDT) and four single-pole, single-throw
(SPST)], one analog output and six digital
inputs. Figure 1-14 provides the I/O Module
output connector and adapter pin assign-
ments. Table 1-3 provides the I/O Module
Input, Output and Power Specifications. If
the I/O Module is installed in a Platform, the
24 VDC power is derived from the Platform
and no external power is required.
Note that the connector on the I/O Module
is a male 25 pin sub D shielded connector.
It is equipped with EMC protection devices,
but it is essential that no more than 24V be
applied to any of its pins. This includes the
analog output which is isolated from the
metallic shield, but which also has EMC de-
vices which restrict the maximum common
mode voltage allowed.
I/O Modules can provide standard auto-
matic range change between high and low
ranges. A user-adjustable time delay is
available to prevent range switching caused
by a noisy environment.
FEATURE DESCRIPTION
Output Relays
7 relay contacts (3 relays SPDT, 4 relays SPST)
Contacts rated at 24 VDC, 1 amp resistive.
Input 6 digital inputs and 24 VDC return, 5 mA resistive.
Standard Output 0 to 5 VDC or 0/4 to 20 mA (isolated, software-selectable)
Power Requirements 24 VDC, 3 Watts maximum
Table 1-3. Analog I/O Module Specifications