FEATURES AND OPERATION
2-15
Part No. 001-4090-101/102
2.7.3 SLEEP MODE
In this mode, the unit is always in low power consumption (< 20 mA). Only asserting RTS on the
COM or the SETUP ports can wake-up the unit. When the unit is sleeping, it cannot detect the presence
of a carrier. This mode can be selected from the RSS. The unit will be ready to receive a carrier and
decode data within 45 to 65 ms (depending on radio model and temperature) after wake-up.
2.7.4 REMOTE UNIT WAKE-UP BY DTE
A Remote Terminal Unit (RTU) connected at an Integra-H (configured as remote) can be
awakened by raising either RTS inputs.
DOX mode:
either COM or SETUP ports RTS can be used for wake-up. Data from DTE cannot
wake-up the unit.
RTS mode:
the SETUP port RTS can be used for wake-up without causing transmission.
2.8 EXTENDED PREAMBLE
This selection is used to extend the transmitted synchronization time when the Integra-H is used
as remote or master in networks with repeaters. This time is in addition to the standard transmitter turn-
on time. Depending on user's protocol, add 5 to 10 ms for each repeater the Integra-H communicates
through in the network.
2.9 OPTIMIZING YOUR SYSTEM
Detailed system engineering is beyond the scope of this manual. However, there are some simple
tips that can be used to optimize performance of a radio based SCADA or telemetry system.
Choose the best protocol
Some SCADA devices allow a choice of more than one operating
protocol. In some cases, performance can be improved by selecting a different protocol. Contact
Technical Service for assistance.
Check timer settings
Polling protocols issue a poll and wait a certain time for a response.
Integra-H adds a short amount of delay to each poll and response (typically in the order of 60 to 70 ms).
Timer settings that are too short may cause erroneous indication of missed polls, in which case the
application may retry or continue to cycle, ignoring the missed station. In this case, the response may
collide with the next poll, further increasing errors. Setting an adequate timer margin will avoid problems
and maximize performance.
Avoid flow control
Set the Com port baud rate to a value less than or equal to the radio network
speed (4800, 9600 or 19200 b/s). In a polling system, this will prevent buffer overflow with possible
missed transmissions. If the port baud rate must be set higher than the radio network speed, you may
have to limit message length to prevent possible buffer overflow. Integra-H will exert a flow control
signal (CTS dropped) if buffers are almost full, but not all DTE honor such signals.
