Covidien INVOS 5100C - Table 9-4. Digital Output Troubleshooting Chart; Troubleshooting Signal Strength Indicator (SSI); Troubleshooting the Digital Output

Troubleshooting Techniques
Operator's Manual 9-9
9.8.4
Troubleshooting the Digital Output
Table9-4.provides problems that may be encountered while outputting data and a list of the
possible causes and action to correct for each problem (see section 7.4 Using the Digital Output
Port).
9.8.5 Troubleshooting Signal Strength Indicator (SSI)
The signal strength indicator (SSI) reflects the strength and stability of the signal that is used to
make an rSO
2
measurement. The SSI depends on physiological factors (different from individual
to individual) and possible disturbances from secondary sources/influences in the monitor’s envi-
ronment. An inherent benefit of the technology is the ability of the device to determine rSO
2
values from very small signals.
The SSI scale ranges from one to five bars, with five bars being the highest. Generally, the SSI
symbol will read five bars. However, rSO
2
values displayed on-screen with one through four stable
SSI bars are also reliable. It just means the rSO
2
values are being generated from a signal intensity
that is lower than normal.
When only one SSI bar appears, it may be an early warning that rSO
2
values on-screen may soon
cease if the signal continues to degrade. Similarly, bars fluctuating rapidly between five through
one bar (rather than appearing stable) may also reflect a signal that could soon be lost. In these
scenarios, when the signal is lost for one channel, the rSO
2
value is not displayed for that channel
No display Defective CPU board
Service the INVOS™ system.
1
Defective monitor
Service the INVOS™ system.
1
Defective inverter board
Service the INVOS™ system.
1
1. For additional troubleshooting assistance, contact Covidien’s customer service department at 800 635 5267, Customer.Service-RMS@Covidien.com,
www.covidien.com, or via an authorized repair representative.
Table9-3.INVOS™ System Troubleshooting Chart (Continued)
Indication Possible cause Action
Table9-4.Digital Output Troubleshooting Chart
Indication Possible Cause Action
Selecting CASE HISTORY in the
Digital output menu produces
the “COM PORT UNAVAILABLE”
message on the screen
The digital output port is not connected
to the PC with a null modem cable.
Verify the connection of the monitor to
the PC with a null modem cable.
The wrong COM port is specified in the
HyperTerminal™* program.
Verify the correct COM port is specified.
No data received or transmission
is scrambled.
The HyperTerminal™* settings are not cor-
rect.
Verify the HyperTerminal™* settings are
correct.