I've never seen this "loop" structure in a circuit diagram before.

  • Pin 6 has a line that loops around the lines from pins 5 and 9.

  • Pin 7 has a line that loops around all other lines, except the ?resistor? between pins 1 and 6.

Nellcor Pulse Oximeter Pinout

NOTE: This pinout diagram is for the db9 connector on a Nellcor Pulse Oximeter


The loops represent a shield around cable that then connects to the connector pin indicated by the line from the loop.

In your example there is a two wire pair that is shielded and then that is contained with some other wires and an overall outer shield.

| improve this answer | |
  • \$\begingroup\$ Follow up question, should the shielding be connected to ground? \$\endgroup\$ – Zak Aug 28 '18 at 1:00
  • 9
    \$\begingroup\$ The shields should be connected to the pins shown in the diagram. \$\endgroup\$ – Peter Bennett Aug 28 '18 at 1:15
  • 4
    \$\begingroup\$ No. The schematic is for a connector, cable and sensor assembly. Appropriate connections for the shields are determined by what is on the other side of the D-9 connector pins 6 and 7. \$\endgroup\$ – Michael Karas Aug 28 '18 at 2:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.