E-Stop Survey Results

We are updating and unifying our automation control systems at City Tech, and since we strive to model best practices in the industry, I put out a call for respondents to a survey asking questions about Emergency Stop (E-Stop) utilization in the entertainment industry. I was mostly interested in what was the most widely-used connector and control voltage, but (as often happens) I ended up learning something altogether different.  More on that shortly; let's go through the results:

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Many automation systems are installed permanently, so I think that accounts for the "I don't use connectors" being the largest response. After that was CPC connectors, and 37.5% of the CPC respondents use 9 pins (apparently this is an older Fischer Technical standard, more on that later) 37.5% use 6 pins, and 25% use 4 pin (I know this is a Hudson Scenic standard, since we own one of their winches). The next most-widely used connector was  XLR, and 42.9% use 3 pin (which I wouldn't think is a great idea due to the potential cross plugging with audio stuff), 28.6% use 6 pin, 14.3% use 4 pin, another 14.3% use 5 pin.  Other connectors mentioned were Harting (2 responses), Lemo,  and PowerCon.  

While there isn't any sort of consensus on connectors, there was a clear favorite voltage:

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Only one person was using AC, so 97.3% use DC.  This is in line with my recent I/O Voltage Survey, which you can see here.

Most people who have an indicator light on their E-Stop controls have it light up when the E-Stop is activated, killing power to the equipment:

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72.97% of those indicator lights are Red.

It's a bit unfortunate that 40.54% of the respondents are not following any formal safety standards:

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Since 86% of the respondents were from the USA, it's not surprising that those who did follow a standard used the NFPA standard.

But what was most interesting of all in the responses were two notes from Scott Fisher of Fisher Technical Services (FTSI) and Alan Hendrickson, professor of automation at the Yale School of Drama (one of my alma maters). Yale has already moved to and FTSI is in the process of moving to "Fail Safe over EtherCAT" (FSoE), an Ethernet-based safety system. From the EtherCAT Technology Group site:

The open protocol Safety over EtherCAT (abbreviated with FSoE "FailSafe over EtherCAT") defines a safety related communication layer for EtherCAT. Safety over EtherCAT meets the requirements of IEC 61508 SIL 3 and enables the transfer of safe and standard information on the same communication system without limitations with regard to transfer speed and cycle time.

Beckhoff EtherCAT I/O seems especially popular in our industry, and they have a safety terminal range as well.  Being a big proponent of anything over Ethernet (I did write a whole book on the topic, after all), that seems to be the most flexible approach.  If it's affordable, that's likely going to be my choice, but I'll know more when I get a chance to research further.  

Thanks to everyone who took the time to respond!