SiePortal

The integrated platform for your product selection, buying and support workflow - bringing together Industry Mall and Online Support.

Products & Services
- Menu temporary not available
- Menue temporary not available
- {{item.title}}
Support Support
{{(apiData.Support | filter:{'rank':1}:true)[0].title}} Support
- Menu temporary not available
- Menue temporary not available
- {{item.title}}
MySiePortal MySiePortal
{{(apiData.MySiePortal | filter:{'rank':1}:true)[0].title}} MySiePortal
- Menu temporary not available
- Menue temporary not available
- {{item.title}}
Cart ({{apiData.CartCount}})

Navigation

Cannot communicate with M-Bus(meter bus) device using CP340.

6/22/2010 2:30 PM	Rate (0)
andrius Posts: 12 Rating: (0)	Hello, anybody has experience ? I have CP340-RS485 and heater meter device with meter bus protocol-RS485. I send simple ascii telegram SND_NKE to slave: '$10$40$01$41$16'. After send_done:=true, i try to receive data from slave for ack signal $E5, but nothing happens. Speed the same 2400 bps, addresing is corect:01,data bits:8, stop bit:1, parity even. Anybody have any idea ? Andrius
andrius Posts: 12 Rating: (0)
Suggestion To thank Quote Answer

6/22/2010 2:49 PM	Rate (0)
smiffy Platinum Expert Joined: 1/17/2007 Last visit: 3/10/2025 Posts: 1557 Rating: (540)	I assume that you are using the FB P_SEND to send the data. I have looked at the MBUS protocol and your request looks fine, so there is no reason why the device does not respond. What FB are you using to receive the data back? P_RCV? What status code (STATUS) is being reported from the receiving function?
	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...
Suggestion To thank Quote Answer

6/23/2010 6:22 AM	Rate (0)
andrius Posts: 12 Rating: (0)	Yes, i'm using P_RCV FB.Status and error codes are the same: null.
andrius Posts: 12 Rating: (0)
Suggestion To thank Quote Answer

6/23/2010 9:51 AM	Rate (0)
Kaulquappe Posts: 3093 Rating: (324)	Hallo Andrius, how did you setup the cable? Are the pins of the communicatio partner named R(A) or R-? R(A) of CP340 is equal to R-. Regards, Kaulquappe
Kaulquappe Posts: 3093 Rating: (324)
Suggestion To thank Quote Answer

6/23/2010 10:47 AM	Rate (0)
andrius Posts: 12 Rating: (0)	Hello, I connect device's RS485 contact A to CP340 pin 4 and device's contact Bto pin 11. No connection GND between device and CP340.
andrius Posts: 12 Rating: (0)
Suggestion To thank Quote Answer

6/23/2010 10:49 AM	Rate (0)
andrius Posts: 12 Rating: (0)	I use CAT5 UTP cable.
andrius Posts: 12 Rating: (0)
Suggestion To thank Quote Answer

6/23/2010 10:55 AM	Rate (0)
Kaulquappe Posts: 3093 Rating: (324)	Hello Andrius, is contact B of the device + or -? You must connect - to - and + to +. Regards, Kaulquappe
Kaulquappe Posts: 3093 Rating: (324)
Suggestion To thank Quote Answer

6/23/2010 11:25 AM	Rate (0)
andrius Posts: 12 Rating: (0)	I think contact A must be - and B contact +.In the device's manual i can't find this information. I will try to change cables pozitions.May be this will be a solution ?
andrius Posts: 12 Rating: (0)
Suggestion To thank Quote Answer

6/23/2010 11:35 AM	Rate (0)
Kaulquappe Posts: 3093 Rating: (324)	Hello Andrius, as you are sure to use the right protocol parameters, it may be a solution. Wrong wiring is an error that occurs time and again with RS485. Regards, Kaulquappe
Kaulquappe Posts: 3093 Rating: (324)
Suggestion To thank Quote Answer

Share this page:

Share this page on...