12
HR-2000 Introduction and Operation
To reduce battery drain when
not using the Radio-Link option,
with the HR-2000 unit on, press
both the
PEAK/HOLD
and the
ON/OFF
key. This disables the
radio portion of the software
and will increase battery life.
Introduction
Addresses
High frequency signals are
subject to absorption by the
ground and the atmosphere, as
well as reflections from metallic
surfaces. For low power sys-
tems, it is normal that varia-
tions of range will be experi-
enced, even in “open air”
conditions in different environ-
ments. Due to combinations of
absorption and reflection,
pockets with weak and strong
signals will be experienced
inside the range.
The dominant absorption factor
is the ground. As a general
rule, the higher the antennas
are above the ground, the
better the signal.
The HR-2000 operates as a remote keyboard and display for the ED-2000plus
electronic dynamometer. Communication between the HR-2000 and the
ED-2000plus takes place in RS-485 format via cable or low power radio
communication.
The HR-2000 has the following communication parameters "hardwired" into
the device.:
• Communication mode: RS-485 half duplex
• Baud rate: 2400 bits per second
• Own address: Configurable
• Initial remote address: Last address used
Addresses are important with the ED-2000plus and HR-2000 because of the
manner in which they communicate. The HR-2000 sends out a signal (poll
signal) requesting that the instrument with a specific address send its display
reading. The ED-2000plus looks at the poll signal that the remote sent and
determines if the address matches. If it does match, the ED-2000plus re-
sponds with its reading.
The concept of addresses is relatively transparent if the system consists of a
single ED-2000plus and an HR-2000. The system will communicate with little
(if any) addressing ever required. However, if several ED-2000plus instruments
are in the same area, they each need to be uniquely identified so that the
HR-2000 knows which ED-2000plus it is talking to.
If several HR-2000 remotes are in the same area, each remote needs to know
when it is its turn to use the airwaves. This is also accomplished by assign-
ing the remote a unique address, and by telling it how many other remotes
are in the area.
The following pages describe the operation of the HR-2000, both in one-on-
one and multiple applications.
