On April 19, 2011 at 13:39, avgenius1 said...
Sorry Stamp but I have to call this like I see it. RJ45 to DB9 adapter = lazy technician. I cannot tell you how many times I have had techs blame my code for a device not communicating only to find out that they grabbed an already terminated adapter off the van and it was pinned wrong. If you solder you will always get it right.
You're a funny guy. You are telling me that every soldered DB9 connector has been pinned out right? I can't believe that even you believe that. If you are going to get it wrong with the adapter, why will they get it right with the soldering iron? Seems like bad thought process to me.
To me the adapters allow a clean neat setup for little time input, and allow the wire to be used for other purposes. This is more efficient in terms of money and time.
There are many reasons NOT to use CAT cables for serial communications. The primary reason is the noise cancelling effect of the twisted pairs. Yeah yeah, you've never had a problem. Congrats on having an awesome streak of luck. Serial communications is limited in distance to 50' at 9600 Baud, by specification.
More misinformation. There is nothing in the RS232 specs that say things won't work over 50'. What is even worse, is you say Serial Communications. RS485 is serial communications, and blows your 50' out of the water.
[Link: arcelect.com]You even discuss RS485 later in your response, but fail to address that it will work over longer lengths. Seems like you are applying "DirecTV installer mentality". The same mentality where DirecTV installers are told that CCS RG6 will not work, so they attempt to charge the customer to rerun the cable. Those of us who understand why DirecTV doesn't use the CCS, realize that on short runs, it will work just fine. Unfortunately, you are falling into this trap of spouting absolute numbers without understanding when they are valid.
I have seen many instances where the installers have only pulled a CAT5 cable for serial communications and it didnt work. The length was about 35 to 40 feet on each of those problem jobs. The units had to be switched to IR control and that sucked from my standpoint as I lost all real feedback from the device so all my time programming (and counting on that feedback) was wasted. It will happen at some point in your career and inevitably it will happen when you must have 2 way comm and cannot get a new wire there. Pull the right wire and you won't have that problem.
No, they didn't have to be switched to IR... you just don't know the tools to get the job done. I guess this is another situation where the Non-pro DIYer has to teach the Pro! LOL
In such a situation, you could keep the serial communication, for a minimum amount of money, and have a rock solid connection. Two of these bi-directional RS232 to RS485 converters, and for less than $50, you can run the serial data rate up to 115.2KBaud.
[Link: serialcomm.com]
