Hard vs. Soft Patch

Joined
Aug 9, 2005
So this may be a stupid question, but I figure it's good to know. What is the difference between soft and hard patch? I know that on my schools light board (Express 48/96) in patch there is only channel and dimmer numbers. So what is the difference? And does it matter? Also, does it even exist on the newer systems? Cause my school has an ancient strand century 80, so I'm just curious if there is a difference in patching on new equipment.
 

cutlunch

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Jan 12, 2005
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Auckland, New Zealand
The difference is the same as you find in computers. Soft patch equates to software ie you tell the lighting board how you want the channels on the board to equate to the actual dimmer addresses .

Hard patching equates to hardware. If you want to change the channel - dimmer assignment you have physicaly to change wires.

You are right this was more pre-DMX when analog dimmers had a wire for each channel. I don't know how often hard patching was used in the past because of the time needed to rewire. I did it once on a rack of analouge dimmers when one circuit on a main light failed. The memory desk we used didn't have soft patching so we rewired the control signal to another dimmer whose light could be done without.

Soft patching can be quite flexible depending on your board. As well as allowing more then one dimmer per channel. You can set proportional levels for example 50% so that when the channel is at 100% the dimmer will only ever get a signal up to 50%.

Edit:
After reading Soundlight's post I must make a correction to my post. When I am talking about patching I am only talking about changing the control link from the desk to the dimmers. Soundlight is right in what he does is called patching. However as he said to change channel to dimmer assignments he must use a softpatch.
 
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soundlight

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Oct 27, 2005
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NJ & NYC
I run a hardpatch system at my school. It has 102 circuits (coming from the electrics, drop boxes, and floor pockets), and each of those has a wire that is coming out of a box that is about two feet by two feet on top. I have 32 dimmers. Each of the dimmers has 3 input plugs on to it. You can patch any of the 102 circuits into any of the 32 dimmers. This is a basic 3-to-1 hardpatch system. Softpatch can patch any number of dimmers to to any of the faders.
 

disc2slick

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Feb 11, 2004
Location
Key West, FL
To put it simply:

Hardpatch refers to what dimmers your lights are plugged into. Thus to "change the hardpatch" means to physically unplug the light and plug it into a different dimmer.

Softpatch refers to what channels each dimmer is assigned to, and is determined through the "patch" function on the board.

Any patching you do on the board is softpatching, 'Patch by Dimmer' and 'Patch by Channel' are just two different ways of doing the same thing.

-Dan
 

SteveB

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Mar 20, 2004
Location
Brooklyn, NY
One good example of a current use of hard patch is on an ETC Sensor touring dimming system, such as a 48 or 96 dimmer rack.

Inside the rack is a "hard" patch panel that allows the output from a particular dimmer to be sent to a particular pin on a Socapex receptacle. This is very, very useful to assign the dimmer to a particular Soca connector, especially as there are generally more Soca receptacles then dimmers available if it were hard wired 1:1.

SB
 

jonhirsh

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Dec 11, 2004
Location
Toronto, Ontario and Valencia, California
I didnt have time to read the other responses but from glancing over there lengths i think i can simplyfy it even more.

The two types of ways to arange which fixture turns on with which chanel.

Hard Patch = Hardware (fixtures, circuts, Patch Bay, dimmers) these are physical objects.

Soft Patch = Software (console, Routing software) these are software based. Usualy controlls the output of the console to the dimmers. this is not tangable its software based.
 

kingfisher1

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Jul 14, 2005
soft patching on the express also can include assinging channels to other dmx things like scrollers, fog machies, coffe makers, what ever.
 

soundlight

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Oct 27, 2005
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NJ & NYC
Haha! The Doug Fleenor Designs DMX Coffeemaker! I think they also have the DMX shock collar as well...for those spot ops that go to sleep...

I wish that I had a picture of my hardpatch system, because then I could explain it really well. Maybe I need to get a photobucket...
 

kingfisher1

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Jul 14, 2005
its okay, just illistrate it with your hands. oh wait, we can't see them.
 

Radman

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Apr 9, 2004
Location
Franklin, TN
soundlight said:
Haha! The Doug Fleenor Designs DMX Coffeemaker! I think they also have the DMX shock collar as well...for those spot ops that go to sleep...

I wish that I had a picture of my hardpatch system, because then I could explain it really well. Maybe I need to get a photobucket...
Theres no signing up for Image Shack
Just go there, upload, and copy-paste the code.
 

gafftaper

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This has been covered pretty well but I thought I would l throw in a full answer I use for my students to sort of cover the whole topic at once...

To begin with you have to always remember that while they all may have the same number, Channels, Dimmers, and Circuits are NOT the same.
Channels are numbers on the board that tell dimmers to turn on.
Dimmers are power supply units.
Circuits are the wires that connect the lighting instrument to the power supply.

In most modern lighting systems, the default setup is Channel #1, activates Dimmer #1, which sends power to circuit #1. Also in modern systems designers often reprogram the light board so that Channel #5 activates dimmer #1 which sends power to dimmer #1 (this is soft patching). In older systems however, Channel #1, activates Dimmer #17, which sends power to circuit #36 (changing the relation of the Dimmer and Circuit numbers is hard patching).

In the last 15 years or so, the cost of dimmers has dropped quite a bit. Because of this, newer lighting systems are "dimmer per circuit" which means circuit #1 is wired directly to dimmer #1. In the past dimmers were much more expensive than they are now and you often had far less dimmers than circuits. In these systems you had a panel that you used to patch which dimmers powered which circuits. A common patch panel design has a slider that goes up and down for each circuit. Every half inch or so, there is a little notch that the slider clicks into. Each click is a dimmer. You slide each channel up or down until they are all patched into the proper dimmers.

On newer systems we soft patch which dimmers are controlled by which channel primarily for convenience. On old patch panel systems, there is a huge amount of design work spent dealing with the patch and wattage load. It isn’t uncommon to find yourself in this situation: you are trying to use 16- 750 Watt and 50- 500 Watt, and 12- 1000 Watt instruments, on 40 circuits, with 12- 2.4K dimmers and 24-1.2K dimmers… hmm if I repatch the specials at intermission I can do it.
 

leistico

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May 22, 2006
Location
KS
Heh...all this talk has me going down memory lane... reminds me of the system I learned on, back in high school. It was a panel and rack custom manufactured for the school, 20 channel 2-scene preset with a manual fade group as well. Turn the key on on the board and you could hear "rrrrrRRRRR-WHAM!!" as the relays kicked in, up in the dimmer room by the makeup rooms. It was a patch-panel system (something I think every lighting tech/designer should spend at least two or three shows negotiating, just so they know how it was done without computers, to foster a bit of creative problem-solving). Looked like an old telephone operator's panel, SR in the wings. 20 dimmers (one dimmer per channel) with four sockets to each dimmer, plus an ammeter on the panel with four sockets for load testing. IIRC, we had about 160 circuits, from the catwalk, two dead-hung electrics on stage and floor pockets. Twist-lock connectors on the instruments and electrics and pockets, weird channel-iron spring-nut-bolt method of hanging instruments, trick sliders on the panel that worked when they were in the mood to...

...yeah, and I walked to school every day in the snow, uphill both ways. LOL
 

gafftaper

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My first high school experience was pre-light board. You had this giant box back stage with handles about a foot long on it. Each handle represented a circuit. You could select which dimmer ran it by spinning a dial from 1-10. There were two rows of dimmer handles. By twisting the handle you could lock it into "fade" position. In this position pulling down one handle pulled them all down. My first day using it the teacher said, "Don't hook anything into dimmer 4 because you can see flames inside the panel when you use dimmer 4". It's one of those things that's impossible to explain with out picture but if you were there you remember it well.