Honeywell Intelliguard 9000 Installation Instructions Manual page 30

INTELLIGUARD 9000™
Jumper and Switch Configuration
Refer to the Quick Reference section for jumper settings.
Detailed explanations follow.
DTE/DCE Configuration
A DIP shunt is used to select DTE or DCE configuration. For
the RS-232 to 485/422 Converter to appear as a DTE device,
place the DIP shunt jumper in socket XWIB. For the RS-232 to
485/422 Converter to appear as a DCE device, place the DIP
shunt jumper in socket XWIA.
Frame Ground /Signal Ground
Jumper W7 ties signal ground to frame ground. The position is
left open at the factory. If signal ground is to be connected to
frame ground, solder a 100 ohm, 1/2W resistor in location W7.
A wire jumper may also be used. Care must be taken to
ensure that ground circulating currents are limited to
acceptable levels.
Half/Full Duplex Operation
Jumper W8 selects half-duplex or full-duplex operation. Set
W8 to the 2-WIRE position for half-duplex operation. Set W8
to the 4-WIRE position for full-duplex operation.
NOTE: When the jumper W9 is in the ON position, the RS-
485 driver is always turned on to enable transmis-
sion of data. Therefore, half-duplex transmission
cannot be performed.
CTS Delay
When the device transmitter is first turned on, an unstable
carrier signal is transmitted for several milliseconds. If data
was sent during this period, it would be received as distorted
information. Setting a CTS delay on the RS-232 to 485/422
Converter allows the communications link to settle down
before data can be sent.
RS-232 to 485/422 Converter as DCE
When the RS-232 to 485/422 Converter is configured as a
DCE device (DIP shunt in position XWIA), jumper W9 controls
the amount of delay from the time the RTS Jumper W5 (in the
A-B position) is received true until CTS is asserted true. If W5
is in the B-C position, CTS will be inhibited if an RS-485
carrier detect signal is present when RTS is raised. To select a
CTS delay period, set jumper W9 to the 0, 10, or 30 ms
position. Regardless of the delay setting selected, when RTS
goes false, CTS immediately goes false. If jumper W9 is in the
ON position, CTS follows RTS.
RS-232 at 851422 Converter as DTE
When the RS-232 to 485/422 Converter is configured as a
DTE device (DIP shunt in position XW1B), CTS is not
supported.
RS-485 Driver Enable
The RS-232 to 485/422 Converter RS-485 driver can be set to
enable in one of three ways: by RS-232 control signals, by
data, or constantly on.
74-3047—1
Driver Enabled by RS-232 Control Leads
If the equipment raises CD or RTS, set the RS-485 driver to
enable by one of these leads. If the equipment does not have
the capability to raise CD or RTS, set the RS-485 driver to
enable either by data, or constantly enabled.
In order for a RS-232 control lead to enable the RS-485 driver,
W15 must be in position A-B and W9 must be set for 0,10, or
30 ms.
When the RS-232 port is selected as DTE (DIP shunt in the
XWIB position), the RS-485 driver will be enabled when CD
(pin 8 of the RS-232 connector) goes true.
When the RS-232 port is selected as DCE (DIP shunt in the
XW1A position), RTS enables the driver.
Driver Enabled by Data
The RS-485 driver can also be enabled without requiring an
RS-232 control lead to be asserted. When jumper W15 is
placed in the B-C position, the driver is enabled when data is
received on the RS-232 port of the RS-232 to 485/422
Converter. As soon as the first bit of the first character is
received at the RS-232 port, the RS-485 driver is enabled and
an internal timer is started. The timer begins its time out on a
low (0) to high (1) transition of data. When the timer times out,
the RS-485 driver is disabled. Jumper W17 allows this timeout
delay to be set for 0.15, 0.7, 2, 7, or 70 ms.
NOTE: There is a limitation to using this DATA ENABLES
DRIVER feature. At data rates above 64 Kbps, the
first character in the data stream will be garbled by
the Converter. If higher data rates are required,
transmit a <break> if possible, or a <nul> character
before each message. This enables the RS-485
driver, activates the timer and allows the message to
be transmitted without errors. The receiving device
ignores the first character received.
Driver Constantly Enabled (4-Wire Only)
The RS-485 driver can be constantly enabled by setting
jumper W9 to the ON position.
Half-Duplex Turnaround Delay
When operating in half-duplex mode (jumper W8 in the 2-
WIRE position), the RS-232 to 485/422 Converter adds a
small delay each time it stops transmitting data and prepares
to receive data. This delay allows the RS-485 interface and
transmission-line time to stabilize, thus reducing the possibility
of garbled data being received at the end of a message.
The turnaround delays are 0 (W16 in position A), 0.1 ms (W16
in position B), 1 ms (W16 in position C), 5 ms (W16 in position
D) and 35 ms (W16 in position E).
RS-485 Interface Terminated or Unterminated
Some distortion on the twisted-pair line may be caused by
impedance mismatch from the different devices connected to
the line. To help eliminate this type of distortion, the RS-485
interface can be terminated with a resistor network at the
receiver input pins (RXA and RXB) via switch S2. When S2 is
placed in the TERM position, the resistor network is
connected across the line. When S2 is placed in the UNTERM
position, no connection to the resistor network is made and
the line is not terminated.
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