Product manual

B Protocols TAC Xenta Server – Gateway, Technical Manual
160 (184) Schneider Electric Buildings AB, June 2011
04-00124-06-en
B.6.2 BACnet PTP Interface
The BACnet PTP interface driver is added into the network pane of
XBuilder, as shown for a SrlSim example network in the following
screenshot.
Interface Properties
• Port Type – In most cases the RS-232 port option will be selected.
The RS-485 option should only be used in the rare case of a target
half-router using either RS-422 or RS-485.
• Baud Rate, Parity, #Data Bits, #Stop Bits – All the communica-
tion parameters, such as baud rate and parity, must be the same as
that of the target half-router.
• Subnet# – Allows the target BACnet network number to be
entered (0–65535). The entered number should correspond to the
unique number of the BACnet network that contains the target
devices. Normally the target BACnet network should be the same
as the one that is physically connected to the target half-router.
• Message delay (mS) – Allows an optional interval to be inter-
spersed between poll messages. Normally left blank or set to zero
to minimize the time the Xenta 913 takes to read all the required
input values.
Some slower half-routers may generate an excessive number of
response time-outs when being polled at the maximum rate. In
these cases a non-zero delay may be required, but some experimen-
tation will be required to determine the smallest practical delay. In
severe cases a delay of up to 500mS may be entered, but this will
significantly reduce the rate at which the Xenta 913 can read values
from the target devices.
• Write Priority – Allows an optional write priority to be entered
(3–16, with 3 being the highest priority and 16 the lowest). Can be
used to assign the gateway application’s priority versus other
applications should they also write a value to a single object. Nor-
mally left at the default write priority of 12.