problem about time of loading page in citect scada

[mostafa]

hi dears i am working on a project,in this project i have one page and inside of this page i want to display information some sensors,suppose 20 sensors,but my problem is when this page wants to be loaded, it takes about 5 seconds to page be loaded,my interface is serial rs485 with baud rate 9600,what is my problem?

[BobB]

Serial connection is the problem I would think - have not used serial connection into Citect for about 15 tears as it is pathetically slow. Had one job on serial and a page used to take about 12 seconds to load - use something else. Added to that 9600 is even worse. If there is parity check as well that will help to slow it down more.

[mostafa]

it means that there is not another way for decrease time of loading page?

[BobB]

Increase serial speed would help a bit - say 19200, 38400. Best to get rid of the serial interface and use something else. Serial is a PITA! You do not mention your PLC brand but Ethernet IP, Controller Link, DH+? Edited May 7, 2013 by BobB

[mostafa]

unfortunately this controller device, just support from serial communication with baud rate 9600! The interesting thing is that I have 5 of these control centers have been connected to each other (like a chain)! Edited May 8, 2013 by mostafa

[BobB]

Daisy chain is common for RS485 - the less devices you have on the chain the faster it is. You could perhaps put in more RS485 cards and address each one separately from each card - that would probably speed things up a fair bitr.

[michael G]

+1 and we are assuming that you already are using address blocking. (minimizes the number of messages needed to get the data)

[mostafa]

Does it by setting the parameter "[modbus]Block" is different?

[michael G]

Not what I was talking about What I was meaning was for example: a display page uses - Var1 and Var2 IF Var1 is address 40010, Var2 40011 - can be read in one message IF Var1 is address 40010, Var2 40310 - needs two messages and takes longer and at 9600 you want to use the least number of messages Edited May 9, 2013 by michael G