Power Supply/Sequencer Module (Pssm); I/O Modules - Emerson ControlWave Instruction Manual

ControlWave I/O Expansion Rack Instruction Manual

1.5 Power Supply/Sequencer Module (PSSM)

1.6 I/O Modules

1-6
Boot/Downloader FLASH
Boot/download code is contained in a single 512 Kbyte FLASH chip.
Boot FLASH also holds the value of soft switches, audit/archive file
configurations, and user account and port information.
FLASH Memory
The CPU module contains 32 MB of FLASH memory. The FLASH
memory holds the system firmware. The FLASH does not support
hardware write protection.
System Memory (SRAM)
The CPU module has 2 MB of static random access memory (SRAM).
During power loss periods, SRAM enters data retention mode (powered
by the CPU backup battery). Critical system information that must be
retained during power outages or when the system has been disabled for
maintenance is stored here. This includes the last states of all I/O points.
The Power Supply/Sequencer module (PSSM) takes power from an
external bulk DC power supply and then provides power through the
ControlWave housing/backplane to all installed modules.
The PSSM operates from +22.2 to +30V (dc) and ships from the factory
with a nominal input supply configuration of 24V.
The PSSM includes:
 ON/OFF system power switch(es) for each power supply board
 Pluggable terminal block to connect the external power supply
 Watchdog output connector to signal a watchdog failure to an
external device
 Status LEDs
Chapter 2 includes instructions for installing and configuring the PSSM.
The ControlWave I/O expansion rack supports analog input, analog
output, digital input, digital output, universal digital input, isolated
RTD, and isolated low level analog (thermocouple and mv) input
modules for either local or remote field device wiring termination.
Refer to Chapter 3 for information on specific I/O modules. Figure 1-3
shows a typical I/O module housing.
Terminations are pluggable and accept a maximum wire size of #14
AWG. Each I/O module connects to the backplane using a 110-pin male
connector and to its associated terminal block assembly using a 44 pin
header.
Introduction Revised Aug-2015