Why does MNS prefer RS-485?

What is RS-485

RS-485 is a standard defining the electrical characteristics of drivers and receivers for use in balanced digital multipoint system. It is a form is serial communication between computers and devices. The different types of communication standards are published by the Telecommunications Industry Association.

What are the advantages of 485

• Ability to communicate over longer distances
• Ability to communicate at faster communication rates
• High immunity from noise interference
• The use of differential signals

Images

	RS232	RS423	RS422	RS485
Differential	no	no	yes	yes
Max number of drivers Max number of receivers	1 1	1 10	1 10	32 32
Modes of operation	half duplex full duplex	half duplex	half duplex	half duplex
Network topology	point-to-point	multidrop	multidrop	multipoint
Max distance (acc. standard)	15 m	1200 m	1200 m	1200 m
Max speed at 12 m Max speed at 1200 m	20 kbs (1 kbs)	100 kbs 1 kbs	10 Mbs 100 kbs	35 Mbs 100 kbs
Max slew rate	30 V/μs	adjustable	n/a	n/a
Receiver input resistance	3..7 kΩ	≧ 4 kΩ	≧ 4 kΩ	≧ 12 kΩ
Driver load impedance	3..7 kΩ	≧ 450 Ω	100 Ω	54 Ω
Receiver input sensitivity	±3 V	±200 mV	±200 mV	±200 mV
Receiver input range	±15 V	±12 V	±10 V	–7..12 V
Max driver output voltage	±25 V	±6 V	±6 V	–7..12 V
Min driver output voltage (with load)	±5 V	±3.6 V	±2.0 V	±1.5 V

 

Links

http://en.wikipedia.org/wiki/RS-485

http://www.lammertbies.nl/comm/info/RS-485.html

My First Day.

First day at Micro Nursecall Systems. Was able to set up my work station along with my work PC. Unfortunately I am having problems with the Dual View display. The two Samsung monitors that I am using only have VGA connections. We need to find the correct converter for the Display Port adapter.

Windows 7 Installation

Had to do a fresh format of an old laptop hard drive and then install Windows 7 on the hard drive. There was a slight problem with the product key on the bottom of the laptop. It had become a little difficult to distinguish some of the characters of the product key do to extensive use by the client – Ciaran. I sat for a little while exchanging B’s for 8’s, G’s for 6’s and visa versa only to find out that I had in fact put a Vista CD into the CD-ROM and not Windows 7.

Next time I should definitely make sure that I am installing the correct software.

After a quick CD change, the installation process went surprisingly smoothly. The product key was one of the two possibilities we had guessed.

Once the installation was complete I made sure that all the Windows updates were done. I then installed Office 2010 for Ciaran.