Manual

December, 1998 Page 13 of 28 949-1270
Wire the communication lines as shown on Page 7. Wiring for the
RS-485 is run from control to control in a daisy chain fashion with a
termination resistor (120 ohms) across the transmit and receive
terminals of the last control in the chain.
Select the control address and communication baud rate with the
Addr and bAUd menu items in the Secure Menu. THE BAUD RATE
AND ADDRESS MENU ITEMS WILL TAKE EFFECT ON THE NEXT
POWER UP OF THE CONTROL. BE SURE TO POWER CYCLE
THE CONTROL BEFORE USING THE NEW BAUD RATE AND
ADDRESS.
In operation, you have the option of preventing a write command
from the host computer. To prevent the host from writing to the
control change the LOrE menu item in the Secondary Menu to LOC.
To allow the host to write commands to the control set LOrE to rE.
(The host does have the ability to change the LOrE state, but it is not
automatic.)
If your system depends on constant reading or writing to and from
the host, you may wish to set the No Activity Timer (nAt) to monitor
the addressing of the control. When the LOrE is set to rE and the
nAt is set to any value other than Off, the control will expect to be
addressed on a regular basis. If the control is not addressed in the
time set by the value of nAt, then the control will display the error
message CHEC LOrE. To clear the message set LOrE to LOC.