351579-YTS-B-0608
Johnson Controls Unitary Products
5
EPROM
- This is “nonvolatile” memory, meaning it will not be
erased on a power loss. This memory is usually programmed
prior to assembly of the controller. Since this memory is not
changed during normal operation of the
Simplicity
®
control, only
basic operation instructions are stored in this type of memory.
EEPROM (Double “E” Prom)
- Is also non-volatile, but this
type of memory requires a special process to be written to. This
memory can be written to and changed by the microprocessor.
This is the type of memory that the control program is stored in
the
Simplicity
®
control.
ROM
- Read Only Memory is non-volatile but can not be written
to. This memory is programmed only once before the controller
is assembled. ROM contains instructions specifically for the
internal microprocessor computer in the controller.
FIRMWARE
- “Firmware” is software, program instructions or
applications, but stored in EPROM or ROM memory.
RAM
- Random Access Memory is a volatile memory. It will be
erased when a power fail occurs. This memory is used as a
kind of “scratch pad” for the controller. Temporary instructions
and information such as an output controlling action like driving
the economizer dampers open is stored here. When a power
loss occurs or if the controller is sent a manual reset using a
control push button, this memory is cleared and initialized.
Other filtered inputs include temperature and humidity sensors.
You should be aware of this filtering effect because it will
appear the controller is not acting as fast as you may think it
should. In reality, it is acting and controlling on these time-
averaged and weighted values.
FAULT TOLERANCE
- Fault Tolerance of the
Simplicity
®
control
involves two issues: Hardware fault tolerance deals specifically
with the electrical characteristics of the controller - how much
over voltage or power surge the controller can withstand before
damage occurs, and whether internal comparisons are verifying
that the control is calculating and communicating properly.
Software fault tolerance in this technology consists of comparing
results to previous values and to reasonable values.
COMMUNICATIONS BUS
Networked communications may also be new to you. It relates
to connecting several Millennium
®
rooftop units to a network
that can be monitored and controlled remotely from network
computer workstations. You will find this typically on large
installations where central control, monitoring, and energy
management issues become a critical factor in operating a
large complex such as a manufacturing facility.
The
Simplicity
®
Control has the ability to be networked into a
larger system using the MODBUS communication protocol. A
communication protocol is simply a set of rules that determine
how two systems communicate with each other over some
medium such as a pair of wires, phone line, radio waves, etc.
The transmission medium may also be called a gateway,
pathway, or bus. An “open” protocol such as MODBUS is a
publicly published set of rules that any equipment manufacturer
can use to network into another manufacturers equipment.
OPTIONAL ModLINC TRANSLATOR
OVERVIEW
The ModLINC translator operates as a Modbus
®
Client providing
an interface between a BACnet
®
control system and devices that
communicate using the Modbus
®
RTU protocol. The ModLINC is
preconfigured to provide an interface to YORK UPG products
equipped with an Intelli-Comfort or
Simplicity
Elite™ controller
and allows monitoring and control by a third-party BACnet
®
Building Automation System (BAS).
The ModLINC communicates using the Modbus
®
RTU protocol
on one port and BACnet
®
MS/TP. By providing different
communication protocols on the two ports, data can be
retrieved from and provided to two different systems.
The ModLINC mounts inside the control panel of the UPG unit
and utilizes 24 VAC power from the unit's control transformer.
One port is connected to the UPG controller. The other port
must be connected to the BACnet
®
network.
The ModLINC translator is preconfigured to obtain operational
data points from the controller and expose them on a BACnet
®
network.
"The ModLINC device is primary a control offered and
configured by York's ESG (Engineering Systems Group). The
device is designed to tie into and function with a BACnet
®
MS/TP network. The device can be used with other BACnet
®
MS/TP systems, but a qualified controls contractor must be
involved. UPG cannot support the ModLINC device beyond its
hardware functionality and cannot guarantee functionality with
other third party BAS devices."
Please refer to the ModLINC Installation/Application manual
Part Number 126367.
COMPONENT DESCRIPTION
This section describes the main components of Millennium
®
Simplicity
®
control. These components consist primarily of
controllers, hardware to handle signal input and control output
and the Tstat interface terminals.
THE
Simplicity
®
CONTROLLER
Simplicity
®
is a proprietary, microprocessor-based controller for
use in HVAC applications. The controller provides monitoring
and control for either VAV or CAV for a total of 22 outputs.
WIRING AND TERMINATION, COMMUNICATIONS
Most connections to the
Simplicity
®
Control are by wiring
harnesses. There are also screw terminal connections for
thermostat inputs and for communications via an RS-485 port.
COMMUNICATION ADDRESS
The communication address button (lower right of the display)
is used to identify a Millennium
®
rooftop unit to a network, and
“capture” the next available network address for that unit.
Millenniums can be networked together for centralized
