Hey guys,

i'm using Lyngso serial communication module " SAM electronics". i'm trying to read a device modbus addresses (holding registers) starting from (35000). so the full address is (435000). yet i found out that this module has limitation and can only read four digit address only up to (9999).

any suggestions ?

 

You can't really get 6 digit addresses in Modbus. the range is 0 to 65535with an offset of 1 so you can read registers 400001 to 406536.

perhaps a call to the manufacturer of the modbus master device is in order. some of them have some ways to shift where it is actually reading by some fixed amount to get around this unnecessary limitation.

you may need to buy a more appropriate Modbus moudle. How did you select this one? did you not notice in the specs for the module it only handled 4 digit addresses?

 

Hello,

I wrote this for a guy the other day.

MODBUS addressing in a nutshell.

The first character defines the register type. 0, 1, 3 or 4.

All the remaining characters are the register number.

0xxxxxxxxxxxxxxxxxxxxxxxxx is still coil at address xxxxxxxxxxxxxxxxx.

00000000000000011 is coil 11.

00011 is coil 11. 5 digit format

000011 is coil 11. PeakHMI uses this format, 6 digits.

So, just put a 0 in the spot after the register type, 0, 1, 3 or 4 and then the register number if the length of the address is not 6 characters.
40345 changes to 400345.

Conclusion, I am not sure if you are using the Lyngso TO read the register from another device or read the register FROM the Lyngso. If the latter, the above should apply. If the former and the Lyngso will not let you enter an address > 9999 then you might be stuck.

Or if the program you are using to read FROM the Lyngso will not let you enter an address > 9999 then you might be stuck.

Good luck,

Mark
http://www.peakhmi.com/

 

Are you sure it is 4 digits BASE 10 as opposed to 0x7FFF or 0xFFFF BASE 16?

Also if you are addressing the starting register as 35000 then technically it is Holding Register 435001, yes?