A bench scale that only shows a number on its own display is doing half a job. Fitting a TTL to RS-232 board lets the Jadever JCE and JWE send every weighing to a PC or a label printer — and the wiring is simple enough that the difficulty is usually the pin numbering, not the electronics.

Fitting the board

RS-232 and relay output board for electronic scales — RS-232 / relay output board.

Installing the RS-232 board in a Jadever scale — The board installed.

Board options available

RS-232 + RTC + relay + printer (TDP, SH-24 TP, ZEBRA, GODEX)
RS-232 + RTC + relay + light tower
RS-232 + RTC + relay + PC

If you need alarm setpoints, choose the RTC-RS232-Relay board. Only that version makes the three switching functions — Hi, OK, Lo — available.

Output pin layout on the RS-232 relay board — Output pins on the board.

Connecting to a PC

Two things have to be set before anything appears on screen:

Have a program on the PC ready to receive — a COM port test tool such as Terminal.exe is enough
On the scale, set Print Mode to Prt.Co, which makes it send continuously

The PC end is a DSUB9 male; the board on the JCE/JWE is a DSUB25 female. Check the pin diagram rather than assuming a straight-through cable will work.

Pin connection between scale and PC serial port — Scale to PC pin connection.

Serial settings

Parameter	Value
Baud rate	2400, 4800 or 9600
Data bits	8
Parity	None
Stop bits	1
Character set	ASCII

What the scale sends

Each frame is a start bit, eight data bits sent LSB first, a parity bit and a stop bit. The data itself is a fixed-width ASCII string ending in CR LF:

Field	Content
Prefix	`G/N.W.:` for gross or net weight, `U.W.:` for unit weight
Sign	+ or −
Value	Padded with spaces to a fixed width
Unit	`kg`
Terminator	CR LF

Because the field widths are fixed, software reading this string can slice it by position instead of parsing it — which is why the padding spaces matter and must not be trimmed on the way through.

Weight string received in a terminal program — The string arriving in a terminal program.

Integration note

KALA Technical Notes

When nothing arrives at the PC, the cause is nearly always the print mode setting or the pin mapping rather than a faulty board. Tell us the scale model and what you are connecting to, and we will confirm which board option and cable you need.

Email Technical Support

● Interface boards, cables and label printers for bench and platform scales.

Kala Scale

Adding an RS-232 Interface to a Bench Scale