3: JUMPERS AND COMMUNICATION
SNAP-LCM4 User’s Guide
12
Setting the Controller Address
Each Opto 22 controller connected to a host computer must have a unique address between
1 and 255 (1 and FF hexadecimal). Zero is not a valid address. The following table shows possible addresses
and their corresponding jumper settings. The factory default is 1.
The most significant bit is 7 and the least significant bit is 0.
Setting the Host Port
The controller host port jumpers H0 and H1 determine which port the controller’s default host task will be
started on. Because the host task is required for communication to any of Opto 22’s programming or interface
software, the default host port must be set to the port attached to the host computer. The factory setting is
COM0.
You can change the host port to COM1, as shown in the table at
right. However, in general it should not be used this way with I/O,
since COM1 was designed to communicate with I/O.
Address Jumpers.
COM Port
H0
H1
COM0
In
In
COM1
Out
In
ARCNET
In
Out
Ethernet
Out
Out
