Instruction Manual

Card Setup
Sealevel Systems COMM+2/EX Page 2
Card Setup
The COMM+2/EX contains several jumper straps which must be set for proper operation.
Address Selection
Each port on the COMM+2/EX occupies eight consecutive I/O locations. A DIP-switch is used to set the base
address for these locations. Be careful when selecting the base address as some selections conflict with existing
ports. The following table shows several examples that typically do not cause a conflict. SW1 sets the I/O address for
port 1 of the COMM+2/EX and SW2 sets the address for port 2.
Address Binary Switch Position Setting
Hex A9 A0 1 2 3 4 5 6 7
280-287 1010000XXX Off On Off On On On On
2A0-2A7 1010100XXX Off On Off On Off On On
2E8-2EF 1011101XXX Off On Off Off Off On Off
2F8-2FF 1011111XXX Off On Off Off Off Off Off
3E8-3EF 1111101XXX Off Off Off Off Off On Off
300-307 1100000XXX Off Off On On On On On
328-32F 1100101XXX Off Off On On Off On Off
3F8-3FF 1111111XXX Off Off Off Off Off Off Off
Figure 1 - Address Selection Table
The following illustration shows the correlation between the DIP-switch setting and the address bits used to
determine the base address. In the example below, address 300 is selected as a base. Address 300 in binary is XX11
0000 0XXX where X = a non-selectable address bit.
ON
12345 6 78
ENA3A9
Figure 2 - DIP-Switch Illustration
Note: Setting the switch ‘On’ or ‘Closed’ corresponds to a ‘0’ in the address, while leaving it ‘Off’ or ‘Open’
corresponds to a ‘1’.
Refer to Appendix A for common address contentions.