Power line carrier

(Fwd) Interface

Hello people , We are going to be involved in a utility SCADA project with special status . I mean the communication line is PLC(Power Line Carrier) with following specification (600/1200bps) but our selected RTU needs a 9600 bps communication line for complying with the client timing request (2 to 10 sec between sending a control command and receiving its answer back ) if they will be connected via conventional modems . We are looking for an interface (e.g. intelligent modem) that can decrease time delays( for following configuration) as much as possible , if any. If such interface has 3 RS485 inputs and one output for connecting to PLC , it would be fine !

A- PLC comm. line spec. is:

a-Terminal Arrangement :Four wire

b-Termination Impedance :600 Ohm +/- 10%,isolated and balanced

c-Transmission Level :0dBm nominal,adjustable to 12dBm in at most 4dBsteps

d-Receive Level Range :0 to -30dBm without adjustment

e-Selectable Signaling Mode:-Standard Modes : 600bps CCITT V.23 1200bps CCITT V.23 -PLC Modes: 200bps FSK with center frequency at 2760HZ +/-90HZ

f-Bit Error Rate :Operation with bit error rate of less than 1:100000 in the presence of signal to noise ratio 15 dB

g-Data Band Frequency :2100 to 3400 HZ

h-Voice Band Frequency :300 to 1800 HZ

B- Substations are in "Y" configuration and their layout is : SUB#6---PLC---SUB#5----PLC--------SUB#4 MDS----microwave---SUB#9----PLC----SUB#8---PLC---SUB#7---PLC-------------SUB#4 SUB#1SUB#2------PLC-----SU B#3----PLC--------SUB#4 SUB#4 in an intersection point in this "Y" configuration. MDS : MASTER DISPLAY SYSTEM , SUB:SUBSTATION ,PLC:POWER LINE CARRIER Approximate distances between SUBs are 10 to 55 Km. Please do'nt hesitate to contact us if you need further information, or you have solution(s), comments and/or advices ! Best regards,

 Saeid Shoarinejad
 President
 ATA Technics Inc.
 #250,1220 Kensington Road ,N.W.
 Calgary , AB, Canada , T2N 3P5
 Ph.:(403)270-3601
 Fax:(403)270-3484

RE: DNP vs. IEC vs. UCA

Hello Jim Just what I was looking for :-). Thanks for the information. I've conceived a mini-SCADA system for the Hidroelectrical power plants here in Madeira as part of my master thesis. We used ModBus as the system is a protype, but if the company accepts future development we are considering going for DNP3.0

RE: DNP vs. IEC vs. UCA

Hi Nuno, For your information , there are a lot IEDs with capability of measurement over 300 electrical parameters , storing logged information for apprx. 30 days and even more (depends on your required data for logging) and much more capabilities that are very useful for power plants as well . If you are interested in the matter , please contact me at your convenience . Best regards,

Saeid Shoarinejad
 President
 ATA Technics Inc.
 #250,1220 Kensington Road ,N.W.
 Calgary , AB, Canada , T2N 3P5
 Ph.:(403)270-3601
 Fax:(403)270-3484
 Email:atatech@cadvision.com

RE: DNP vs. IEC vs. UCA

Try Power Measurement Limited's ION 7xxx range of devices. Can store lots of power measurements and power quality data for days/weeks depending on onboard memory. They have a web page. Regards Hansell Williams ========================== At 10:11 AM 23-05-97 +0000, you wrote:

Ref: c:\scada\051997\msg00000.xml