BEWATOR COTAG 4101-2, Руководство по установке, Страница: 74 / 158

4101-2 Controller Installation Handbook
8-6
transmit a message upstream without first having been polled
is when it is an F-type Comms module connected directly to
the computer, or to the modem at a remote site.) See section
on Operating for description of LEDs on power up.
7
Downstream transmit and receive LEDs (D6 and D5
respectively): the Tx LED (left hand one of the pair) lights when
the Comms module polls a Controller or Comms module
downstream; the Rx LED lights when a downstream Controller
or Comms module responds with a message. During operation,
the Comms module polls downstream devices very quickly so
the Tx LED appears to be lit continuously. See section on
Operating for description of LEDs on power up.
8
Upstream RS485 connector (CONN1): for connecting the
Comms module to another Comms module upstream.
9
Upstream RS232 connector (CONN2): for connecting the
Comms module to the host computer, or to an upstream
modem at a remote site.
10
Downstream RS232 connector (CONN3): usually for connecting
the Comms module to a downstream modem or other device
that requires RS232.
11
Downstream RS485 connector (CONN4): for connecting the
Comms module to all the Controllers on a branch, or to a
downstream Comms module.
Comms layouts
To understand how to connect a Comms module and which type to
use (4230, 4232 or 4235), you need to know its position in the
system and the number of Access Points in the system.
The most common system - 1 Comms module
Computer
4230 C/M
Controller Controller Controller Controller
d/s RS485
u/s
RS232 d/s
RS485
u/s = upstream
d/s = downstream