FX Network

[WKla 0]

Hello, I need to build a network from 3 PLC's: 2xFX3U and 1xFX1N. One of the FX3U PLC's would be the master and the other two would be slave. The Master should read 8 Integers and 8 Boolean devices from FX1N Slave, and up to 24 Integers and 8 Boolean devices from FX3U Slave. I have some questions: 1. I've made some tests with N:N Network using 2 FX1N PLC's, but I don't know if different type of FX PLC's could be mixed. 2. Using Pattern 2, only 8 Integers and 64 Boolean devices could be transferred, so I want to use some mechanism of synchronization to read 24 Integers from FX3U Slave. Could this be possible? Have anyone else that tried this before? I made some test but looks like the Boolean devices aren't refreshed in the same time as Integers, so I look for some information about how these devices are synchronized. Any other ideas are welcome, maybe another type of network communication. Thank you.

[Inntele 60]

Hi WKla, 1. You can use the given type of PLCs in N:N-network simultaneously, because restriction for group is related with Parallel Link protocol. 2. If you want to transfer more than 8 registers between PLCs, it can be done with index. I.e. the master uses one of a data communication register as index that to indicate which data block is necessary to read or to write. Also you should remember that data in devices, which appointed to N:N network, are refreshed independent on scan. Therefore you should not use directly these devices in the program to analyze the data in them, and you have to copy refreshed data to another data block and than to use the last in the sequence of control. If you will have another questions, please don't hesitate.

[WKla 0]

Thank you for the reply, Inntele. I was thinking of the register index, too. I wrote the following code for Slave: First I put the transfer data (data SET 1,2,3) to register, and then, to the next M8012 pulse set the M1100 bit (that enables Master to read source). I'm doing this because I don't know if the Integers are transfered the same time as Boolean, and I prefer to wait until the data will be transfered and then read it. The hole reading cycle will take 600 ms. [/b]LD M8012 (* 100 ms pulse *) OUT M80 (* Data Set 1 *) LDP M80 AND= D40 K0 MOV K40 (* data SET 1 *) D10 (* D10 to D17= INT Slave 1 -> Master *) LDF M80 AND= D40 K0 RST M1101 (* M1064 to M1127= Bool Slave 1 -> Master *) RST M1102 LDP M80 AND= D40 K1 SET M1100 (* enable read Data Set 1 *) (* Data Set 2 *) LDP M80 AND= D40 K2 MOV K50 D10 (* data SET 2 *) LDF M80 AND= D40 K2 RST M1100 RST M1102 LDP M80 AND= D40 K3 SET M1101 (* enable read Data Set 2 *) (* Data Set 3 *) LDP M80 AND= D40 K4 MOV K60 D10 (* data SET 3 *) LDF M80 AND= D40 K4 RST M1100 RST M1101 LDP M80 AND= D40 K5 SET M1102 (* enable read Data Set 3 *) LDP M80 INC D40 AND> D40 K5 RST D40[b] Code for the Master: Simple read the data when the bit turns ON. [/b]LD M1100 MOV D40 D41 MOV D10 D40 LD<> D40 D41 (* data syncronization error detection *) SET M40 (* error syncronization 1 *) LD M1101 MOV D50 D51 MOV D10 D50 LD<> D50 D51 SET M50 (* error syncronization 2 *) LD M1102 MOV D60 D61 MOV D10 D60 LD<> D60 D61 SET M60 (* error syncronization 3 *)[b] I also have tested the simple method: change the Integers and the Boolean devices in the same time, in the Slave, and the read the data on Bit pulse, in the Master. Seems to work fine but I don't want to take any chances. If you have any ideas of how to make the reading process faster and in the same time to be safe, please write it. Thank you.

[Inntele 60]

Hi WKla, The sample below without time strobe should work much more faster. N_N_network.zip I hope the idea and comments to the program would be clear for you. As alternative to N:N-network for the data transfer can be used Modbus-RTU protocol. Edited 15 Jul 2010 by Inntele