adccommunitymod (AutomationDirect) asked a question.
Created Date: March 30,2009
Created By: DPC
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Hi All, I have a system which consists of the following: a) DL06DR, with ECOM100 (1 unit) b) Ethernet switch c) PowerLogic EGX100 Ethernet Gateway (2 units) d) Modbus slave devices connected to the gateway The PLC is connected to the ethernet switch. The modbus slaves are serially connected to the gateway and the gateway (with IP address) is connected to the switch. There are more than 1 slaves on each gateway. Each gateway has slave no.1,2,3. So there are 2 gateways with slave no. 1,2,3, with different gateway IP address. The problem is here - How do i access data from the different slaves with the same slave ID but different IP address? What instructions should i use in the ladder program. I have used Modscan simulator (TCP/IP) and have successfully retrieve data from the slave. Its just how should i access from the PLC. Really appreciate you guys help here. Thanks in advance!
Created Date: March 30,2009
Created by: jackson
You need to use the NetEdit utility for what you are trying to accomplish. This is available in the free downloads section of the ADC website and 'usually ' gets installed with DirectSoft.
Once you have NetEdit, you click on your ECOM100 module and choose the 'Peer to Peer Config '. You would add a Device and choose Modbus/TCP. You will then see a Unit ID: field to which you would specify the node number of the serial slave device you want to access.
In the ladder rung, you would specify this Device Number in the first LD box. See the ECOM manual for specifics on how to setup the ladder code for sending commands.
Created Date: March 31,2009
Created by: DPC
Thanks for the reply. But i think i left out 1 detail. Actually there is a SCADA connected to the system as well. So that makes the 06 as a slave Am i right? So do i still need the peer to peer config? I have read somewhere that this is only for master PLC.
Anyway i will still try it out but what instruction should i be using? RX,WX?
Created Date: March 31,2009
Created by: Do-more PE
Ethernet is peculiar in that it can be both a Master and a Slave at the same time. So the PLC will be a Slave to the SCADA, but a Master to the MODBUS slaves.
Jackson is correct. You need to set up the peer to peer table for the MODBUS slaves.
Created Date: April 01,2009
Created by: DPC
Thanks All for the reply.
Finally got everything working. Set the Peer to Peer with the unit ID to the slave. And use RX/WX with the V memory equivalent of Modbus to access the slave data.
Created Date: April 13,2009
Created by: DPC
network programming help!
Ok now i got it working but i have a lot of data to poll. I need to use around 70+ rx/wx instruction. Is there anyway to shorten the length of instruction instead of the usual routine? I wrote my program as below:
STRN SP120
ANDE CTA1 K1
LD K115
LD K6
LDA O2000
RX V7370
I have tried to use ECRX. It works but the program will exceed the total memory of the PLC.
Is there anybody who have written a network instruction with 70+ rx/wx?
Created Date: April 13,2009
Created by: franji1
Is there a way you can contiguously block-off the data in the Modbus Slave so that you can read/write multiple values with one instruction?
Created Date: April 14,2009
Created by: DPC
I wish i could. but i can't do that. The slaves are scattered around and the data address are not continuous. Any idea???
Created Date: April 14,2009
Created by: milldrone
I wish i could. but i can't do that. The slaves are scattered around and the data address are not continuous. Any idea???
I do not know your exact situation but if the data addresses are within 125 it might be more time efficient to read all 125 addresses and not pay any attention to the ones you do not want.
I think the RX and WX will do 125 addresses at a time. Atleast I know the MWX and MRX will!
Created Date: March 30,2009
Created by: DPC
Hi All,
I have a system which consists of the following:
a) DL06DR, with ECOM100 (1 unit)
b) Ethernet switch
c) PowerLogic EGX100 Ethernet Gateway (2 units)
d) Modbus slave devices connected to the gateway
The PLC is connected to the ethernet switch. The modbus slaves are serially connected to the gateway and the gateway (with IP address) is connected to the switch. There are more than 1 slaves on each gateway. Each gateway has slave no.1,2,3. So there are 2 gateways with slave no. 1,2,3, with different gateway IP address.
The problem is here - How do i access data from the different slaves with the same slave ID but different IP address? What instructions should i use in the ladder program.
I have used Modscan simulator (TCP/IP) and have successfully retrieve data from the slave. Its just how should i access from the PLC. Really appreciate you guys help here. Thanks in advance!