#dP is making good suggestions to you about NOT using S7 String and instead using Array of CHAR.

There are instructions available with the s7-1200 to convert between array of char and string (both ways).

From the manual found here:
https://dmx.ohaus.com/WorkArea/showcontent.aspx?id=6872

NOTES:
1) Commands sent to the Indicator must be terminated with a carriage return (CR) or carriage return-line feed (CRLF).
2) Alternate command characters may be defined by the user (see Alternate Commands in Section 3.10 in the manual).
3) Data output by the Indicator is always terminated with a carriage return-line feed (CRLF).
4) These commands are only available when Print>Output is set to C11 (see Section 3.9.6 in the manual).

The default serial output format is shown below.
Field:  Weight Space* Unit Space* Stability Space* G/N Space* Term. Char(s)
Length:   9   1      5   1          1      1     1    1        **

*  Each field is followed by a single delimiting space (ASCII: 32)
** Terminating Character(s) - terminating character(s) printed depending on FEED menu setting (CR, LF / 4xCR, LF /
ASCII: 12, refer also to Sec. 3.9.5. in the manual).

Definitions:
  Weight - up to 9 characters, right justified, “-” at immediate left of most significant character (if negative).
  Unit   - The Unit field contains the unit of measure abbrevation in 5 characters, left justified.
  Stability - “?” character is printed if not stable. If weight is stable, a space will be printed instead.
  G/N - “N” printed if weight is net weight, “G”, “B”, or a space (depending on GROSS menu setting - Sec. 3.5.7 of the manual) printed if weight is a gross weight.

------------------------------------------------
NOTE: If the Print Content – Result menu is set to Numeric Only, the Result output only includes the weight field and the
termination characters.

Field: Weight Term. Char(s)
Length:   9     **(above)

If all you want is the weight, configuring the print content - result to numeric only would save you a lot of work receiving the values from the scale, especially when the RS485 receive stop characters are set to the configured termination character(s).  You then just have to detect new data received, convert it to a real number, and you have the weight as a REAL value.

DES Automation

Hi All,

Has anyone ever programmed an RS485, network with Ohaus Weighing equipment.

I have 3 weighers which are networked using RS485, (not MODBUS),
Each weigher is programmed with a separate address 1,2 and 3.
The weigher literature says that you must give it a "Print" signal, and then the weigher will send back the weight.
The signal to the weigher to print must be "@01P", this is the message to weigher 1 to print, for weigher 2 it would be "@02P".

The weigher is programmed to print the weight, which is sent over the network as "@01 85.000kg"

this signifies weigher 1 is 85 kg.

A string is the only thing that will except the "@02P" format.

I have used the Send PtP as a string, and receive PtP also as a string. But this will not communicate with the weigher.

The weigher has a function to send the "print" automatically at a predetermined time interval.

When this function is enabled, the receive light on the CM1241 module in line with the predetermined time interval. So the network is wired correctly, but nothing shows in the registers assigned to the receive block.

ohaus weigher model number = T51XW

optional RS485 module is part number 80500731

Regards

Paul