Tektronix Technical Forums are maintained by community involvement. Feel free to post questions or respond to questions by other members. Should you require a time-sensitive answer, please contact your local Tektronix support center here.

A combined continuity and IR system for testing multiple conductors using a four-wire DMM

Post Reply
xyz6692
Posts: 6
Joined: March 1st, 2016, 10:45 pm
Country: United States

A combined continuity and IR system for testing multiple conductors using a four-wire DMM

Post by xyz6692 » March 1st, 2016, 11:08 pm

Hi All,

I have a 3706A with four 3720-ST cards. I want to use them to measure the continuity and Insulation Resistance of a multi-connector cable as shown in Fig. 7-7 of Keithley Switching Handbook (see attachment). I can't find any channel configuration example in either the user manual or reference manual.

Could anyone help?

Thanks in advance.

F
Attachments
Screen Shot 2016-03-01 at 12.36.02 PM.png
Screen Shot 2016-03-01 at 12.36.02 PM.png (193.99 KiB) Viewed 12998 times

brian.d.smith
Keithley Applications
Keithley Applications
Posts: 402
Joined: June 10th, 2013, 6:00 am
Country: United States

Re: A combined continuity and IR system for testing multiple conductors using a four-wire DMM

Post by brian.d.smith » March 2nd, 2016, 4:10 am

The 3700A Reference Manual page 2-96 begins the discussion concerning "Pole settings and channel patterns". 4-wire is called 4-Pole.

Page 7-16 of the Switching Handbook shows the connections for source and sense. Channels 1-30 are source. Channels 31-60 are sense.

xyz6692
Posts: 6
Joined: March 1st, 2016, 10:45 pm
Country: United States

Re: A combined continuity and IR system for testing multiple conductors using a four-wire DMM

Post by xyz6692 » March 7th, 2016, 11:27 pm

Hi Brian,

Thanks for your reply.

Unfortunately, your reply is for a conventional 4-wire measurement as shown in the Fig. 7-11 in page 7-16 of the Switching Handbook. What I wanted to measure was illustrated in the graph of my original post, the Fig. 7-7 in page 7-11 of the Switching Handbook.

Dale Cigoy from Keithley pointed out to me that the only way to configure as in Fig. 7-7 was to hardwire directly from the Dsub-15 to the outputs of the installed card. For example,
Connect
Dsub-15.1 (2W-Hi) to Slot.3.Output.Lo
Dsub-15.2 (2W-Lo) to Slot.1.Output.Lo
Dsub-15.3 (4W-Hi) to Slot.3.Output.Hi
Dsub-15.4 (4W-Lo) to Slot.1.Output.Hi
Closing slot.1.1015 and slot.3.1015, I can 4-wire-measure a resistor in the exactly same way as in Fig. 7-7 of the Switching Handbook.

Why doesn't Keithley have one pole setting for the backplane A1 and A2, so I can close 1911.Lo to slot.1.output.Lo and 1912.Lo to slot.1.output.Hi, and the same for slot.3?

F

Kenneth P
Keithley Applications
Keithley Applications
Posts: 212
Joined: October 25th, 2010, 1:31 pm
Country: United States
Contact:

Re: A combined continuity and IR system for testing multiple conductors using a four-wire DMM

Post by Kenneth P » March 9th, 2016, 9:11 am

The analog backplane switches are single pull, double throw type. Closing any of the backplane switches close both Hi and Lo at the same time. The Hi and Lo lines cannot be independently closed.
A 3732 Matrix card could give you more flexibility with line routing to the analog backplanes however I believe you don't have such a card.

Post Reply

Return to “Series 3700 Switch System/Multimeter and Plug-In Cards”

Who is online

Users browsing this forum: No registered users and 2 guests