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PLC with 5 RS485 port

Created by: zapotek at: 1/4/2013 1:59 PM (7 Replies)

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1/4/2013 1:59 PM	Rate (0)
zapotek Posts: 23 Rating: (1)	Hello everyone; I need a PLC configuration that has 5 RS485 serial ports. One of these ports will work with Modbus protocol. Other ones are only RS485 port without any protocol. It can be S71200, S7300 or any PLC family. The configuration may have 8 DI/DO module. best regards.
zapotek Posts: 23 Rating: (1)
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1/4/2013 2:05 PM	Rate (0)
UMENCHO Diamond Member Joined: 3/21/2006 Last visit: 10/4/2024 Posts: 10229 Rating: (1181)	That kind of CPU doesn' exist. You will need to use CPs. In order to clarify their number please specify in details what kind of devices will be connected there. Best regards, Hristo Mihalev

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1/4/2013 3:10 PM	Rate (0)
zapotek Posts: 23 Rating: (1)	hi, As you see in the attached figure; there is a device (rectangular block) that has 5 RS485 ports. I will need a plc configuration instead of this device (device is a kind of protocol converter). We will write the plc program. How can we do this witb CPs?. I have a little knowledge about siemens CP modules. thanks Attachment pk1.JPG (358 Downloads)
zapotek Posts: 23 Rating: (1)
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1/4/2013 3:50 PM	Rate (0)
smiffy Platinum Member Joined: 1/17/2007 Last visit: 9/30/2024 Posts: 1546 Rating: (537)	If all the slave devices are RS485 and they are all within a reasonable physical distance of each other, and each device have a unique slave address, you could setup a multi-drop link. This is where you "daisy-chain" all the units together. In this mode, you could use 1 CP to get data from all of the slave units.
	Programming today is the race between software engineers building bigger and better idiot proof programs, and the universe producing bigger and better idiots. So far, the universe is winning...
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1/4/2013 4:54 PM	Rate (0)
zapotek Posts: 23 Rating: (1)	smiffy If all the slave devices are RS485 and they are all within a reasonable physical distance of each other, and each device have a unique slave address, you could setup a multi-drop link. This is where you "daisy-chain" all the units together. In this mode, you could use 1 CP to get data from all of the slave units. thanks for reply. Yes, all slave devices rs485; there are close to each other, each device has unique address. but cp (i think you mean cp5611 a2 etc..) is a PCI card. we won't use a computer. We want to use a PLC (with necessary modules). With the rs 485 ports on the PLC,we will link the slave devices as daisy chainlike the current system.Is it possible to do with a plc? thanks
zapotek Posts: 23 Rating: (1)
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1/4/2013 5:42 PM	Rate (0)
Marcjan Platinum Member Joined: 4/22/2010 Last visit: 5/3/2024 Posts: 5697 Rating: (715)	Hello, A CP is a communication processor, could be for a PC but also for a PLC, the confusion maybe is that for the 1200 series it's called CM, i.e. this oneand for a 300 series it's called a CP. Regards, Marcjan
	Problem solved? Please let us know! Please no technical questions by PM, use the forum sections for your questions.
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1/4/2013 6:16 PM	Rate (0)
UMENCHO Diamond Member Joined: 3/21/2006 Last visit: 10/4/2024 Posts: 10229 Rating: (1181)	How do you connect a CP 340, CP 341, CP440 or CP 441 to a communication partner via the RS 422/485 interface (X27 interface)?

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1/7/2013 9:42 AM	Rate (0)
zapotek Posts: 23 Rating: (1)	Hi again; Your suggstions are useful. We can solve this problem with CP340 or 341 modules. thanks.
zapotek Posts: 23 Rating: (1)
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