The Programmer’s Toolkit
Dec 13, 2011 5:28 PM,
By Patrick Barron
The must-have adapters, connectors, cables, and other accessories to get the job done.
When a programmer goes out to a jobsite they are tasked with much more than simply loading the software into the controller. The main task of a programmer is to test the program to make sure everything works. Being able to test different aspects of the program that was written is a key element to finishing a project. At the end of the project, all of the functions in the system have to work properly, but before the final test, the programmer should be able to test the system on his or her own and identify problems in the software before the final test with the project manager or end-user. Many tools and accessories are useful to a programmer out on a jobsite, so let’s take a look inside the laptop bag of a typical programmer to see what we might find.
Testing Media
Testing a control system involves verifying the operation of the equipment being controlled. Since many pieces of equipment handle audio and video routing, having an assortment of test media available is essential in this process. Opening up my laptop bag, you can find a DVD, a Blu-Ray, an audio CD, and a VHS tape in addition to having a stereo 1/8in. audio cable that can be connected to an MP3 player to use as an audio source. Not only is having the media available important, but the content of the media is important as well. There are many different type of jobsites with different types of end-users, and it is important to pick a wholesome title for each type of test media in order to avoid offending anyone that might be at the site. The site might be a church, a conservative corporate office, or even a place like a doctor’s office where children might be able to view the media being tested. While movies with action sequences, graphic violence, and explosions might make good test media to showcase the audio and video systems, this type of media might be offensive to some people and should be avoided. I have The Lion King Blu-ray, a Norah Jones Live concert DVD, The Wizard of Oz VHS tape, and a Sarah McLachlan audio CD in my bag. This type of material would be hard to offend just about anyone yet it does the job of allowing the programmer to find out if the control is working for the various types of media players such as the Blu-ray, DVD, CD, and VHS.
The Programmer’s Toolkit
Dec 13, 2011 5:28 PM,
By Patrick Barron
The must-have adapters, connectors, cables, and other accessories to get the job done.
Various USB accessories including flash drives, USB hub, memory card reader, IR learner, and serial adapters
Connectors & Adapters
Many types of connectors and adapters are needed when testing switching of audio and video systems and control of RS-232 and IR equipment. Looking inside my laptop bag you can always find:
· Female RCA-to-BNC adapter
· Female BNC-to-RCA adapter
· BNC “barrel” connector, used for connecting two BNC cables together
· Female S-Video-to-RCA adapter
· Male S-Video-to-RCA adapter
· Female 9-pin-to-female-9-pin adapter, used to extend and join two serial cables with male ends; often called a “gender bender”
· Male 9-pin-to-male-9-pin adapter, used to extend and join two serial cables with female ends. Often called a “gender bender”
· Female 15-pin-VGA-to-female-15-pin-VGA adapter, links two VGA computer cables together
Serial adapters, audio cables, IR tester, and audio wiring guide
· Female 9-pin-to-male-9-pin null modem adapter; this is the single most important tool that I use and the one that I use most often. A null modem adapter does the simple task of reversing pins 2 and 3 (transmit and receive) on an RS-232 cable. In most cases, a problem with RS-232 can be solved by reversing the transmit and receive pins, and a null modem cable allows the programmer to quickly do this without soldering or crimping a new cable. Because this adapter is used so often, I normally keep 4 or 5 null modem cables at any given time.
· Phoenix screw-terminal-to-9-pin-female, used for connecting bare wires to a RS-232 port and quickly being able to move wires to different pins without soldering or crimping cables
· 9-pin “loopback” RS-232 terminator. Connect this to the end of a RS-232 cable to test connectivity. This adapter connects pins 2 and 3 inside the housing, which allows the programmer to receive the same signal that is being sent from an RS-232 port. By watching the data being received on the RS-232 port the programmer can test the entire length of the cable to make sure there are no shorts or broken wires in the cable.
· IR tester, connects to a 9V battery, and when a valid IR signal is detected, it emits an audible beep and flashes a red LED.
· Rack key. I keep a standard Midle Atlantic rack key in my bag that comes default with most racks that are ordered straight from the factory. Many times I’ve been on a jobsite unable to test anything because the rack was locked. While there are cases when custom keys are ordered, most of the time the default key is able to unlock a rack and allow testing to begin.
Various audio, video, and serial adapters; power adapter; and mini flashlight as well as a standard Middle Atlantic rack key.
USB Devices
A programmer at a jobsite uses various types of USB devices. USB flash drives are essential to transfer any kind of file in a quick and convenient manner. I usually keep three or four different ones handy, and the new USB 3.0 flash drives are extremely fast and make transferring large files much quicker provided that your laptop has a USB 3.0 connection. You will find a USB-to-serial adapter in my laptop because most laptops are no longer made with a built-in serial port. Many pieces of equipment need to be connected to a laptop with a serial connection for configuration, setup, and programming, so the USB-to-serial adapter is one of the most valuable tools I carry. The basic USB-type-A-to-type-B cable can be found as well as an extension USB cable for cases when a direct USB connection is needed. I also keep a USB-to-micro-USB adapter, which can be used to keep a cell phone charged during a long day when several calls to manufacturer tech support are needed.
Another useful USB device is the IR Learner from Crestron. This is used to capture IR hand controls for devices that are not found in the normal IR database. There are times when the programmer needs to be able to read and write files from various types of media cards, so a multipurpose card reader with a USB connection can be used to read CompactFlash cards, SD cards, XD memory, Sony memory stick, and many other formats. I use this most often when transferring media files sent from a producer on a hard drive or DVD to a media card to be played on a MPEG player. Because a large number of USB devices can be used at the same time, a laptop might not have enough USB ports to connect everything being used. This is where a USB hub can be useful. The last USB item that is essential is a full-size USB wireless mouse. Working long periods of time and having a full-size mouse to use instead of the touchpad on a typical laptop can make using the computer much easier.
The Programmer’s Toolkit
Dec 13, 2011 5:28 PM,
By Patrick Barron
The must-have adapters, connectors, cables, and other accessories to get the job done.
Serial cables and serial tester
Cables
I also include an assortment of video, audio, and control cables in my laptop bag. Here’s a rundown of the cables that I carry:
· VGA-to-VGA cable with audio. This is used to connect a laptop with audio to a wallplate or other type of connector plate that has a VGA connector. Most systems have some kind of VGA signal, and a programmer will already have a laptop while working, so having a VGA cable provides a VGA source that can be used to test switching to a video display and the built in audio cable allows testing of the audio system.
· 1/8in.-mini-stereo-audio-cable-to-dual-RCA; this cable allows an MP3 player or laptop to be connected to RCA audio connectors to provide an audio source to a wallplate with stereo RCA connectors.
· 1/8in.-mini-3-pin-to-4-pin Phoenix; this connector is used to load certain types of wireless Crestron touchpanels. The 4-pin Phoenix connects to the master processor’s CresNet bus and the 3-pin mini connector plugs into the touchpanel to load files.
· 1/8in.-mini-stereo-audio-to-1/8in.-mini-stereo-audio, used to connect an audio player such an iPod or other MP3 player or even a laptop to an audio jack on a computer input plate or wallplate
· 9-pin-male-to-1/8in.-mini-3-pin cable; this type of cable is used to load files to an older generation AMX viewPoint touchpanel.
· RJ-11-to-RJ-11 on retractable spool, used to connect phone jacks to phone plugs on an audioconference system. The retractable spool holds a 6ft. cable in a small space.
· 9-pin-male-to-9-pin-female straight-through cable, used as an extension cable for serial devices. This cable can be used to connect from a laptop to certain Crestron processors and certain audio DSPs. It can also be used as a test cable to verify control of RS-232 equipment. If a serial cable is suspected to be bad or wired wrong, having a known good cable to connect from the RS-232 port on a central processor to the equipment being controlled can verify that the code is good and the problem lies in the cable.
· 9-pin-male-to-9-pin-female null cable; this is a serial cable with opposite genders on either end and the transmit and receive pins crossed inside the cable. It can be used to communicate from a laptop to several types of AMX processors. It can also be used to test a bad serial cable. Often when making a control cable, it is not known if the connection should be straight through or if it should have the transmit and receive pins reversed. By having both the straight-through serial cable and the null serial cable, both types of possible connections can be tested and the problem cable can be fixed.
Network cable tester
Cable Testers
Cable testers are another part of the essential tools that I keep in my bag. There are two primary testers that are extremely useful. One is an RS-232 tester. This type of tester has 9-pin connectors on each end and lights to indicate status of various pins on each end. With the increased use of Cat-5 extenders for video sources, it has become more valuable to have a Cat-5 tester as part of the bag of tools. In my bag I keep a tester that allows me to check simple PASS/FAIL to find faults, and it also detects good connections, open wires, crossed wires, and split pairs. The particular tester I have also checks BNC 50Ω and 75Ω cables.
While not a tester, one item that I use frequently is a cheat sheet that I picked up from Extron showing the proper way to wire balanced and unbalanced audio cables. Most installers might have this knowledge memorized, but as a programmer, I don’t wire audio cables every day and having a sheet as a reminder has helped me on many occasions to identify a problem when testing an audio system.
A control system programmer is asked to perform many complicated tasks while commissioning a control system. Having a laptop alone is not always sufficient to fully test all the functions in a control system. Having the proper tools in your bag can allow the programmer to finalize all aspects of testing before the final walkthrough and signoff with the end-user. The programmer can look good at the end of the job by finding all of the problems with the control system software and having the proper tools to troubleshoot and fix those problems.
