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Sensaphone SCADA 3000 Users manual User Manual

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SCADA 3000 User’s Manual

Figure 3: Transmit Data Logic Diagram

Figure 4: Receive Data Logic Diagram

The following definitions describe the timing parameters.

RTS Hold delay: RTS stands for request-to-send. This hardware signal tells the

radio modem that we wish to transmit data. The RTS signal remains raised until

all of the data has been sent. The RTS Hold delay is the amount of time that the

RTS signal remains raised after the data has been sent. Typically this must be set

to between 10-50ms, but to ensure reliable data transmission, you should check

your radio modem specifications for this parameter.

CTS Timeout: CTS stands for clear-to-send. The radio modem will raise CTS

when it is ready to transmit data. The CTS timeout is the amount of time the

SCADA 3000 software will wait for CTS to be returned from the radio modem

before it gives up.

DCD Time Out (Transmit): DCD stands for data-carrier-detect. The DCD signal

indicates that the radio modem is receiving a carrier signal from another radio

modem. The DCD transmit timeout is how long the software waits for DCD to

drop before raising RTS when transmitting.

DCD Time Out (Receive): DCD receive timeout is how long the software waits for

DCD to drop before it stops waiting for a packet to be received.

Flush Buffers after sending packet: Flush Buffers clears the send and receive buffers

immediately after sending a packet. It can eliminate some noise but is not always

necessary.

The following figure shows an illustration of how a typical radio network might look: