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MFM and MFC Cabling - Break out Box Recommendation



Connecting typical analog Mass Flow Meter's (MFM ... does not have a flow control valve) or Mass Flow Controller's (MFC ... has a flow control valve) to read their output is a challenge for most when doing Flow calibrations.  We will group these two similar devices by just referring to them as MFC's. We offer an MFC Option on our Molbox and provide a basic cable connections kit with this, but this requires soldering and proper insulation/termination of each pin by a person experienced in this to create a reliable cable. Each manufacturer and/or model typically has a different pin out so many cables might need to be made to support the variety of MFC's you might have.


To help with the above challenge we have worked with a 3rd party to provide a single custom solution that will allow you to connect to both 9 and 15 pin MFC's. It uses a break out box (BoB) so that the pinout can quickly be changed to match the different MFC's you see.


Simply re-arrange the banana plug jumpers on the BoB to create the necessary pinout match between the Molbox signals and the MFC signals. This can then be documented for future use when see the same make/model again.


All necessary components can be purchased directly from Tesuto .  We have already worked with them to design the custom cable that will connect from the molbox to the BoB as well as a custom y-cable to connect to either 9 or 15 pin MFC's with the same cable. Here is an overview of this solution:



To make it easy to purchase they have placed all items into a single part number that can ordered from Tesuto. Ballpark pricing on this solution is about $1,150 USD, but this is subject to change and it is a custom solution so will likely have a few weeks lead time. Contact Tesuto directly for most up to date pricing and information:

Tesuto kit part number: "T1000-MOLBOX-KIT"

Here is a list of the included parts and the quantity of each for a better understanding or to purchase individually. 


*** Item 4 quantity of 14 is the maximum needed. In many cases might only need a few patch cables

*** Items 5 and 6 only required if might need to use an external DMM or Power Supply rather than using the MFC Option. An external power supply might be necessary if the MFC's has high power requirements. An external DMM would be necessary if the MFC output is say 0 to 10V as the MFC Option only supports up to 6V.

*** Items 4,5, and 6 banana plug cables are all the stackable type. This will allow connecting multiple pins to one as this is sometimes needed.

*** Items 7 and 8 only needed if will see MFC's that have a female connector on them


Here are a couple sample pics of the nice custom cables:

Y-Cable                                                                          MFC Cable

Y_Cable.jpg MFC_Cable.jpg


When using this solution the Molbox 25 pin connection is re-arranged to reduce the pins down to only a 15 pin connector.  Attached is the BoB Pinout_Template.xlsx that matches this new pinout. It can also be used to document the final pinout matching for each of the MFCs you receive over time once verified reads and/or sets flow as intended. Here is an example based off the same Brooks MFC example given in the Molbox User Manual:


It would be great to share the above templates by sending them to . We will update the attached BoB Pinout_Examples.xlsx as we receive them (each one is in a separate sheet/tab) and continue to make these available to the community in this article.


As a side note, Tesuto has offered to also work directly with you to design a custom MFC cable if prefer a direct cable for each MFC rather than this BoB solution. We can also provide a second opinion on the pinout matching if struggling with this for a specific MFC and/or work with Tesuto to assist in this process too.


As a disclaimer, this is a third party product not manufactured by us so it is ultimately up to you to verify the BoB and/or Cable works as required as there is some risk of damaging the A/D converter in the Molbox and/or the MFC if the pinout matching is improper or similar. Make sure the Molbox is powered of when making any connections and triple check all of these as it can be easy to make an improper connection and blow the MFC Option board which is an expensive replacement (it is a built in Power Supply and DMM).  

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