Hey Guys,
a long time ago i 've used openapc to read my electrical meters via Modbus-RTU. Caused by missing functions in the Modbus-Masters i' ve decided to wait until anyone else asks for. In the past few weeks there were some questions about modbus. So i decided to go on with openapc
Today i've installed an instance in a VM (Win7)
I've tested both Masters (RTU & TCP). I am wondering why it is still not possible to read more than one Word in a single request. One of the most benefit is to read a lot of words in one request and process them in the software. So if i need to read two words (4 bytes) each variable i can read the maximum of 4 variables on a device and the Master is full.
Is there a chance to enhance the master to support up to 32 devices?
The parameters should be (each device):
1) Slave-Address 2) Offset 3) Number of Words to fetch
After that we can discuss about functional blocks to process the incoming values an seperate them to pipe them to an LCD-Display in Control-Room.
Thanks a lot.
Hi Ralf,
so what you need is just one parameter that specifies the number of words to be read starting from the current offset?
As an example: lets say you use an offset of 20000 and a number of 10 then the output of the plug-in should emit the values read at offset
20000, 20001, 20002, 20003, 20004, 20005, 20006, 20007, 20008, 20009
These values would be given in serial oder, means the plug-in would emit 10 values directly after each other which would have to be demultiplexed afterwards.
Kind regards
Jim
On 06 February 2014 at 19:01 Ralf Blicker mail@ralfblicker.de wrote:
Hey Guys,
a long time ago i 've used openapc to read my electrical meters via Modbus-RTU. Caused by missing functions in the Modbus-Masters i' ve decided to wait until anyone else asks for. In the past few weeks there were some questions about modbus. So i decided to go on with openapc
Today i've installed an instance in a VM (Win7)
I've tested both Masters (RTU & TCP). I am wondering why it is still not possible to read more than one Word in a single request. One of the most benefit is to read a lot of words in one request and process them in the software. So if i need to read two words (4 bytes) each variable i can read the maximum of 4 variables on a device and the Master is full.
Is there a chance to enhance the master to support up to 32 devices?
The parameters should be (each device):
- Slave-Address
- Offset
- Number of Words to fetch
After that we can discuss about functional blocks to process the incoming values an seperate them to pipe them to an LCD-Display in Control-Room.
Thanks a lot.
-- Ralf Blicker mail@ralfblicker.de _______________________________________________ openapc-devel mailing list openapc-devel@lists.fedorahosted.org https://lists.fedorahosted.org/mailman/listinfo/openapc-devel
-- Kind regards
Jim Hart
http://www.lasermarkingsoftware.com http://www.openapc.com
Follow us at Twitter: https://twitter.com/#!/openapc
Hi Jim, you're right.
Please think about the 32 devices as well.
Is a demultiplexer already available? Am Donnerstag, den 06.02.2014, 20:05 +1000 schrieb Jim Hart:
Hi Ralf,
so what you need is just one parameter that specifies the number of words to be read starting from the current offset?
As an example: lets say you use an offset of 20000 and a number of 10 then the output of the plug-in should emit the values read at offset
20000, 20001, 20002, 20003, 20004, 20005, 20006, 20007, 20008, 20009
These values would be given in serial oder, means the plug-in would emit 10 values directly after each other which would have to be demultiplexed afterwards.
Kind regards
Jim
On 06 February 2014 at 19:01 Ralf Blicker mail@ralfblicker.de wrote:
Hey Guys,
a long time ago i 've used openapc to read my electrical meters via Modbus-RTU. Caused by missing functions in the Modbus-Masters i' ve decided to wait until anyone else asks for. In the past few weeks there were some questions about modbus. So i decided to go on with openapc
Today i've installed an instance in a VM (Win7)
I've tested both Masters (RTU & TCP). I am wondering why it is still not possible to read more than one Word in a single request. One of the most benefit is to read a lot of words in one request and process them in the software. So if i need to read two words (4 bytes) each variable i can read the maximum of 4 variables on a device and the Master is full.
Is there a chance to enhance the master to support up to 32 devices?
The parameters should be (each device):
- Slave-Address
- Offset
- Number of Words to fetch
After that we can discuss about functional blocks to process the incoming values an seperate them to pipe them to an LCD-Display in Control-Room.
Thanks a lot.
-- Ralf Blicker mail@ralfblicker.de _______________________________________________ openapc-devel mailing list openapc-devel@lists.fedorahosted.org https://lists.fedorahosted.org/mailman/listinfo/openapc-devel
-- Kind regards
Jim Hart
http://www.lasermarkingsoftware.com http://www.openapc.com
Follow us at Twitter: https://twitter.com/#!/openapc
openapc-devel@lists.stg.fedorahosted.org