Blue Heat/PCI User’s Manual, Connect Tech Inc.
Revision 0.11 32
Blue Heat/PCI RS-422/485 (6+2 model)
The Blue Heat/PCI RS-422/485 (6+2 model) offers full RS-422/485 support in hardware like the
other Blue Heat/PCI RS-422/485 models. The modes include full duplex, half duplex, and multi-
drop slave. The Blue Heat/PCI RS-422/485 (6+2 model) offers the following additional
functionality.
Tri-state Control
The Blue Heat/PCI RS-422/485 6+2 model allows you to tri-state the line drivers on power up.
To tri-state the drivers on power up please make certain there is no jumper installed across the
pins on jumper block JI. Please refer to Figure 4 for the location of J1.
Line Bias/Termination
You can use jumpers J2, J3, J4, J5, J6, J7, J8, J9, J10, J11, J12, and J13 to terminate and bias
TxD ±, RxD ±, RTS ±, and CTS ± on the RS-422/485 ports 7 and 8. Please refer to Figure 11 for
a partial schematic of the RS-422/485 circuit for the Blue Heat/PCI RS-422/485 (6+2 model)
and Figure 4 for the location of J2, J3, J4, J5, J6, J7, J8, J9, J10, J11, J12, and J13.