Specifications

ELAN AUDIO - SENTINEL / RCU-01 RCU01R02 PAGE 15/49
7.2 Host / RCU Communications
Because SENTINEL communicates with an RCU via a serial connection it must know which serial port ( COM port ) to
use. At any time SENTINEL could receive an incoming alarm packet so it must know at all times which serial port to
monitor for data.
For most users the selected COM port will be either COM1 or COM2. If the port is already in use, perhaps by a serial
mouse, or doesn't exist then SENTINEL will warn the user and prompt them accordingly.
Packet Response Delay.
SENTINEL communicates with the RCU using a master - slave communications system. This system requires the
master to send a communications packet and that the host respond to that communications within a timeout period. It
is the master's responsibility to check for responses. For most communication between SENTINEL and the RCU,
SENTINEL is the master, however for alarm transactions the RCU is the master.
Because SENTINEL can use different communication systems with different communication delays the timeout period
needs to be different for the various communication mediums. The packet response delay is the maximum amount of
delay that the master will wait for a response from the slave. The default values should be sufficient for most systems
and are shown on the Site Record Sheet. Do not change these if you are not sure, as communication reliability
may be compromised.
Host Modem Initialisation. (Only applies to PSTN or MOBILE connection modes.)
If any special host modem initialisation parameters are required then they can be entered here. SENTINEL will send
this string to the modem before each dialing attempt.
NOTE: Do not use &W type commands that write the modem configuration to the internal EEPROM in the modem. These
EEPROMs have a limited number of write life cycles and would soon fail if written to at every dial attempt.
To guarantee modem operation for the Host, the following string must be entered into the window.
s0=2&c1&d2e0m1
This sets auto answer after 2 rings, DCD tracks line carrier, no echo, DTR hang-up, speaker ON till connected.
This is the same string used to set the modem to be used with the RCU with the exception of the 'at' has been omitted
(it is sent automatically) and the &w0 command which has been left off to prevent saving to EEPROM every time the
modem is accessed.
K56FLEX/V90 modems
Note that when using K56FLEX/V90 modems, you may need to add the following initialisation string into the
parameter called “Host Modem Intialisation” contained in the “Configure Host Communications” box to drop the
modulation speed.
“z +ms=11,,,,,,”
This can be done for modems that are used with the RCU-01 also (if they are V90 especially). The string to configure
it becomes;
at&f (as before)
ats0=2&c1&d2e0m1&w0 (as before)
at+ms=11,,,,,, (there are 6 commas)
at&w0
Do this with HyperTerminal at 9600 baud.