I don't make sure, but I think the ScadaLTS no have the modbus 16 function. I need write in 9 registers simultaneously, but the data type that ScadaLTS give does not satisfy my need. I did try to use the type data "fixed length string" but I can't represent the code 0 in ASCII, if I could, it would work.
Finally, I hope to find help and thank you very much in advance.
Modbus function 16 is writing multiple holding register address at once, we cannot write it one by one, and must use fc 16 code. But there is no option to write to multiple address at modbus datapoint. I need this feature also,
Related
I would like to use Input / output module CR203x family with GoLang. The manuals all carry examples for CodeSys. Where can I find the CanOpen sequence to activate, write and read the connected probes?
Normally I would send a COB-ID and 8 bytes but I don't understand if TPDO1 or RPDO1 and even less what the 8 bytes mean. Thank you.
I downloaded the related .eds file but it doesn't help me much.
I'm currently tuning some code written for an STM32F070, where we use one byte on user option byte to keep some flags between Resets, using:
FLASH_ProgramOptionByteData(ADRESSE_OPTION_BYTE_DATA0, status_to_store);
Reading carefully the datasheet from our new STM32F446 lets me think that it is no longer possible to use option bytes to store one user byte...
1 - Am I Right with this assertion ? If not, what did I miss ?
2 - Is there some workaround, not involving to rewrite a sector of the flash ?
I am not an expert on stm32, rather still a beginner, but maybe you could have a look on the RTC backup register to hold your data ?
All,
I am a new user here, and thought I would see if the experts could help me with something I am new to.
I have been given the following statement to try and solve:
The Variable Frequency Drive (VFD) is connected to the PLC by RS485 communication. The speed of the motor (M2) can be adjusted by sending the following command:
STX N DATA ETX , with each separate value having the <> symbols around them.
Data : Length of data is 1 byte, in which the value of S (Slow), M (Medium) or F (Fast) can be sent.
N : Node number of the VFD, with a data length of two byte ASCII.
My question is, how would I type to send this data? It doesn't say whether to use a specific data type to represent, so surely I could just type the data as it is, e.g. STX 1 S ETX?
Othwerside, I'm not sure how to combine the byte representations of the data, representing them in hex, binary or decimal. I'm not sure what is meant by two byte ASCII, is this not UNICODE-16? Also, I'm not sure if I need to send the values of STX or ETX with the data string or not
I hope someone can shed some light on this.
Thanks in advance.
Since the frequency goes from 0-50 Hz, I think we should send data in this range.
So if we want the frequency to be half maximal, we will send 25.
To send this to VFD, we first need to split that number into 2 and 5
The message should read STX 2 5 ETX?
Now we look at the ASCII code table and find 2 and 5.
0x50 = 2
0x53 = 5
We convey everything in a message that reads
STX 0x50 0x53 ETX
The aforementioned S7-300 is recommended for operation. You can also solve this through his TIA portal.
All,
I managed to figure this out with a bit of digging. I simulated it using Siemens S7-300 on TIA portal, and set up communications on a module. I sent the values I wanted using a "move" block, to a value set in the Data Block.
I repeated this for the Node value, making sure the correct data type was chosen, and sent the data through a Send_ptp command block.
Must have got a bit flustered and tired the other night when I was trying it. Hopefully it might help someone in the future.
I am debugging some snmp code for an integer overflow problem. Basically we use an integer to store disk/raid capacity in KB. However when a disk/raid of more than 2TB is used, it'll overflow.
I read from some internet forums that snmp v2c support integer64 or unsigned64. In my test it'll still just send the lower 32 bits even though I have set the type to integer64 or unsigned64.
Here is how I did it:
a standalone program will obtain the capacity and write the data to a file. example lines for raid capacity
my-sub-oid
Counter64
7813857280
/etc/snmp/snmpd.conf has a clause to pass thru the oids:
pass_persist mymiboid /path/to/snmpagent
in the mysnmpagent source, read the oidmap into oid/type/value structure from the file, and print to stdout.
printf("%s\n", it->first.c_str());
printf("%s\n", it->second.type.c_str());
printf("%s\n", it->second.value.c_str());
fflush(stdout);
use snmpget to get the sub-oid, and it returns:
mysuboid = Counter32: 3518889984
I use tcpdump and the last segment of the value portion is:
41 0500 d1be 0000
41 should be the tag, 05 should be the length, and the value is only carrying the lower 32-bit of the capacity. (note 7813857280 is 0x1.d1.be.00.00)
I do find that using string type would send correct value (in octetstring format). But I want to know if there is a way to use 64-bit integer in snmp v2c.
I am running NET-SNMP 5.4.2.1 though.
thanks a lot.
Update:
Found the following from snmpd.conf regarding pass (and probably also pass_persist) in net-snmp doc page. I guess it's forcing the Counter64 to Counter32.
Note:
The SMIv2 type counter64 and SNMPv2 noSuchObject exception are not supported.
You are supposed to use two Unsigned32 for lower and upper bytes of your large number.
Counter64 is not meant to be used for large numbers this way.
For reference : 17 Common MIB Design Errors (last one)
SNMP SMIv2 defines a new type Counter64,
https://www.rfc-editor.org/rfc/rfc2578#page-24
which is in fact unsigned 64 bit integer. So if your data fall into the range, using Counter64 is proper.
"In my test it'll still just send the lower 32 bits even though I have set the type to integer64 or unsigned64" sounds like a problem, but unless you show more details (like showing some code) on how you tested it out and received the result, nobody might help further.
I can't find any help to implement PROV_RSA_AES CSP in c++. is there any article or book to help me out with it?
Here is an article about it.
Here is another one.
i just want to use one, i figured
how to get context but i'm still
thinking about the size of buffer i
need to use for CryptEncrypt() to get
it working with aes256 ? i also want
to use random salt.
AES256 in CBC-mode with PKCS#7-padding (which is the default) will need a buffersize that is the input-data rounded up to the next multiple of 16 (but always at least one byte more). Ie. 35 -> 48, 52 -> 64, 80 -> 96.
There is no salt involved in AES256. Are you talking about key-derivation? Or do you mean the IV?