DF1 half-duplex master configuration

Use information in the following table to configure a DF1 half-duplex master.
DF1 half-duplex master configuration settings
Setting
Description
Media
Specifies the supported media type. The available options are
RS232
 and
RS485
.
RS232
 is the default option.
Control line
Specifies the type of handshake that is used for communication.
  • Select
    No handshake
     for direct point-to-point communication without a modem.
  • Select
    Full-duplex (RTC always ON)
     if both the master and slave are using full-duplex modems.
  • Select
    Half-duplex without continuous carrier (RTS/CTS)
     if both the master and slave are using half-duplex modems.
Error detection
Specifies the error detection scheme for message transmission.
  • When selecting
    BCC
    , the controller sends and accepts messages that end with a Block Check Character (BCC) byte.
  • When selecting
    CRC
    , the controller sends and accepts messages with a 2-byte Cyclic Redundancy Check (CRC).
CRC
 is the default option.
Polling mode
Specifies the polling mode.
  • Message-based polling is set to allow or inhibit the slave from initiating responses.
  • Standard polling is set to allow one or multiple messages to be transferred per node scan.
Duplicate packet detection
Determines how duplicate messages are handled.
  • Select
    Duplicate packet detection
     to ignore duplicate messages.
  • Clear
    Duplicate packet detection
     to acknowledge duplicate messages.
Duplicate packet detection
 is selected by default.
ACK timeout
Specifies the duration that the controller waits for an acknowledgment after transmitting a message.
The value is from 0 through 32767, with each unit increment representing 20 milliseconds.
The default value is 50 (50 * 20 milliseconds, 1,000 milliseconds, or 1 second).
Reply message timeout
Specifies the channel timeout.
If the channel sends a message and does not receive a response within the specified timeout period, the channel will attempt to establish communications again.
The value is from 0 through 65535. The default value is 5.
Message retries
Specifies the count of retry attempts by an slave to retransmit a message packet without an acknowledgment (ACK) from the primary device.
The parameter can be used in noisy environments, where message packets might become corrupted during transmission.
The value is from 0 through 127. The default value is 3.
Pre-transmission delay
Specifies the amount of time before the
Micro800
 controller sends the packet.
The value is from 0 through 65535. The default value is 0.
RTS off delay
Specifies the delayed amount of time between the end of a transmission and the Ready To Send (RTS) drop. It is available when
Half Duplex without continuous carrier (RTS/CTS)
 is selected for
Control line
.
The value is from 0 through 32767. The default value is 0.
RTS send delay
Specifies the delayed amount of time between the activation of RTS and the initiation of a transmission. It is available when
Half Duplex without continuous carrier (RTS/CTS)
 is selected for
Control line
.
The value is from 0 through 32767. The default value is 0.
Polling ranges
Specifies a continuous range of intervals at which the slave polls for data. It is available when
Polling mode
 is set to
Standard
.
You can set a priority polling range and a normal polling range by supplying station addresses for the devices to poll. Slaves in the priority polling range are polled more frequently than slaves in the normal polling range.
Normal poll group size
 specifies active stations that are polled from the normal poll node list.
The value is from 0 through 255.
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