Title: Maximum Number of Blue Heat/PCI Multi Port Serial Adapters in A System
Keywords: Multi-port, PCI Adapters, Blue Heat/PCI, multiport
Date: March 5, 1998
KDB: KDB-213
Revision: 0.00
Author: Support
Distribution: External
Introduction
In Blue Heat/PCI multi board installations, there are some considerations that should taken into account. The following are suggestions that should be visited prior to powering on any system.
1) IRQ’s: A Blue Heat/PCI card requires one IRQ assigned by the Plug ‘n’ Play resources. The Blue Heat/PCI is a PCI compliant Plug and Play device, but IRQ conflicts may still result due to the existance of Legasy (non Plug and Play) ISA bus adapters in the system. One option to avoid this type of conflict is to go into the CMOS setup and exclude the IRQ’s that are required for ISA cards, this will ensure that the PnP will only pick available IRQ’s for the Blue Heta/PCI. The other option is to ensure all your devices are true Plug and Play devices. Furthermore multi board installations of the Blue Heat/PCI can actually share one IRQ, as the PCI bus is capable of sharing IRQ’s amoung add in cards, of course this is usually all assigned by the PCI PnP BIOS. In some computer systems we have found that the user can control which IRQ is allocated for a given PCI slot by going into the CMOS setup and assigning an IRQ to a PCI slot.
2) Memory and I/O: The Blue Heat/PCI also requires I/O address and Memory address space. The PnP BIOS should never have a problem assigning these resources due to the large address space available on PCI bus compatible PC’s.
3) Current Consumption: The typical current consumption of an 8 port Blue Heat/PCI board on the +/-12v rails is in the neighbourhood of 120mA. This of course, varies with the port density and load presented to the Blue Heat board. Typical PC’s have about 400ma – 800ma of current capacity on the -12v rail. This could limit the number of Eight port Blue Heat’s that you could install in a system.
NOTE: The reason the Blue Heat consumes so much +/-12v current is that the high current is required to deliver high baud rates. The following table displays values as recorded during testing at CTI.
Blue Heat/PCI Typical current consumption
Blue Heat/PCI-8
| PCI bus voltages | Current consumption (typical values) |
|---|---|
| 5 | 320 mA |
| 12 | 60 mA |
| -12 | 120 mA |
Blue Heat/PCI-4
| PCI bus voltages | Current consumption (typical values) |
|---|---|
| 5 | 220 mA |
| 12 | 33 mA |
| -12 | 60 mA |
Blue Heat/PCI-2
| PCI bus voltages | Current consumption (typical values) |
|---|---|
| 5 | 200 mA |
| 12 | 20 mA |
| -12 | 20 mA |
End of KDB-213