GE Industrial Solutions Entellisys 4.0 System User Manual - Manual (Page 156)

Discrete I/O 156
10
10.1.2 Software
During CPU start up, the presence of discrete I/O boards is automatically detected. Support of
discrete I/Os does not occur through the option string. The only requirement for this feature is
that the hardware is correctly installed in the CPUs' PMC slots. If a CPU is to be equipped with a
single discrete I/O card, it must be plugged into slot PMC0, otherwise the CPU ignores the board,
execution of FlexLogic program is disabled, and the CPU logs an error event.
10.1.2.1 Redundancy
Software is not affected by whether the discrete I/Os are wired in redundant or non-redundant
configuration.
10.1.2.2 Test mode
Test mode of discrete I/Os enables overriding the states of discrete inputs and outputs. Once the
test mode is turned on, the behavior of each I/O channel is determined separately by test mode
related channel settings. Channels can be set to ignore test mode and act normally, as if the test
mode was not actually turned on, or they can be preset to a high or low state, which overrides a
channel’s actual state. Once the test mode is disabled, all channels function normally. Test
mode can be exited at any time. As a precaution, test mode is automatically disabled when the
CPU is restarted.
10.1.3 Setup
Preparing CPUs to use discrete I/Os takes place in two independent steps: hardware installation
and software configuration. Discrete I/O cards must be installed in a CPU’s PMC slots in the
correct order, starting with slot PMC0, otherwise discrete I/Os do not function and FlexLogic is
disabled. If there is a single card per CPU, it must be installed in slot PMC0. All the cards must be
secured to the CPU's main board using screws that are provided by cards’ manufacturer. Other
hardware installation requirements and software configuration steps are specified in the
corresponding sections below.
10.1.3.1 Wiring
This section describes rules to properly wire the system. Wiring rules are divided into four
sections corresponding to the four major hardware components of the system.
CAUTION: Wiring rules need to be followed very strictly. Any deviation from them might
damage the equipment.