User`s manual

CHAPTER 3
PROGRAMMING ESTEEM FEATURES
3-2
Listed in this chapter are the major ESTeem features and
programming examples on how to use them. These
features are individual building blocks to solve your
application needs. Remember your particular application
my require one or more of these features enabled.
DIGI-REPEATING
The Repeater feature allows an ESTeem to relay it's
respective transmission or packet through a maximum of
three ESTeems to increase the operating range of the
unit. Any ESTeem in your radio network can function as
a repeater for any other ESTeem independent of the fact
that the ESTeem being used as a repeater is linked or
connected to another node. Therefore an ESTeem can
function as a repeater, operational node, or both at the
same time. The data that is digi-repeated through an
ESTeem will not be output through its respective
RS-232C port.
To specify one or more ESTeems as repeaters, the
CONNECT command has been expanded to accept up to
three added addresses as follows:
CONN r1,r2,r3,da
r1 = Address (0 to 253) of first repeater.
r2 = Address (0 to 253) of second repeater.
r3 = Address (0 to 253) of third repeater.
da = Address (0 to 255) of destination ESTeem.
Note
: Address 254 is used for self test and address 255
is used for Global.
When transmitting packets through other ESTeems, the
source ESTeem will automatically adjust it's FRACK
time to allow additional time for the packet to reach its
destination and for the returned acknowledgment. Frack
time takes into account the packet size and the number of
repeaters specified. The ACK still comes from the
destination ESTeem, not the first repeater.
For testing purposes you can answer back to yourself if
you place your source address in the destination address
of the repeater string.
REMEMBER, you can use a repeater address string in
any command that requires a specific address in this
manual.
Example:
SETC r1,r2,r3,da
GLOBAL BROADCAST
Global broadcast is the ability of one ESTeem to transmit
it's message to more than one ESTeem at once. All
ESTeems within radio range will receive the message
whether or not they are connected to another ESTeem or
in command or converse mode. The global message will
have the highest priority over all other traffic on the
receiving ESTeem.
You can put your ESTeem in Global by connecting to
address 255. Address 255 is a non assignable unit
address and is used by the ESTeem CPU to put the
modem in this special mode. When an ESTeem is in
Global the standard ACK protocol from the receiving
ESTeem is disabled, but the 16 bit CRC error checking
on the received ESTeem is still operational.
When you perform CONN 255 <cr> from the
COMMAND MODE the ESTeem will immediately go to
the CONVERSE MODE (* is displayed). All messages
sent will be transmitted globally to all ESTeems in radio
range.
In your ESTeem you have a GLOBAL (on/off)
command. When GLOBAL = On, you will receive
Global transmissions. If GLOBAL = Off you will not
display Global transmissions from other ESTeems.
Factory default is ON.
By using the repeater function, you can go Global from
another ESTeem.
Example:
CONN 10,20,30,255 <cr>. By performing this connect
string you can route from unit 10 to 20, 20 to 30, and go
Global at unit 30.
You can also enable global in more than one ESTeem in
your network and have all units talk to all other units at
the same time.
AUTO TRANSMIT
The Auto Transmit feature of the ESTeem allows the
user to transmit a data packet without filling up the
PACKLEN (packet length) buffer or defining a special
control character using the SENDPAC (send packet)