Spectrum Controls 1734sc-OE2CIH - Manual (Page 13)

Chapter 1: Module Overview 1-5
User’s Manual Pub. 0300272-01 Rev. A.0
Section 1.6
System
Overview
The module communicates to the controller via an Ethernet adapter. The module
receives 5 and 24 VDC power through the PointBus backplane bus interface.
1.6.1 Module Power-up
At power-up, the module performs a check of its internal circuits, memory, and basic
functions. If no faults are found during power-up diagnostics, the module status LED is
turned on. By default, the module powers up with both channels disabled and powered
down until valid configuration information is received.
After power-up checks are complete, the module waits for valid channel configuration
data. If an invalid configuration is detected, the module will generate a PLC fault. Once
a channel is properly configured and enabled, it continuously converts the output data to
a value within the range selected for that channel.
NOTE
If the module loses its IO connection during operation (physically
disconnected from controller or Inhibited), the module functions as if the
Inhibit checkbox was selected during setup. During the interval in which
there is no IO connection, the outputs are disabled. Once the connection is
re-established and a valid configuration is received, the outputs will run
normally.
1.6.2 Module Operation
The 1734sc-OE2CIH has two, single-ended, 4-20 mA and 0-20 mA isolated current
output modules. HART capability is available only on the 4-20 mA range. The module is
fault protected to ±24 VDC. The module also contains a 16-bit DAC. The 1734sc-
OE2CIH has HART Primary Master capability. A dedicated HART modem is used for
each channel for maximum throughput. When HART functionality is enabled on a
channel, the module discovers and establishes communication with HART revision 5 and
greater devices. Once communication has been established, the module automatically
gathers HART PV, SV, TV, and FV data, and monitors device status. The modules
provide a communication bridge via Common Industrial Protocol (CIP) messaging to
HART devices for Asset Management Software and Ladder Programs.