Checkweighing works best when the operator does not have to read the display at all. Fit the relay board and a three-colour light tower to a Jadever JWL or JCL, set the limits, and the scale signals Hi, OK or Lo by colour — the operator watches the lamp, not the numbers.
Choosing the board
Three option boards are available:
- RS-232 + RTC + relay + printer (TDP, SH-24 TP, ZEBRA, GODEX)
- RS-232 + RTC + relay + light tower
- RS-232 + RTC + relay + PC
For this job you need the light tower variant. The pins that matter are Hi-ON, Lo-ON, OK-ON, Alarm for the buzzer, and COM as the common return.
Wiring the light tower
Reading the connector diagrams
In these drawings the white holes represent male pins and the black holes represent female sockets. Getting this backwards mirrors the whole pin numbering, which is the usual reason a correctly wired tower stays dark.
Which connector goes where
The light tower terminates in a single DB-25 male plug. The scale presents two connectors: a DB-9 for RS-232, and a DB-25 female for the tower.
Both are on the same output panel, so identify by shape and pin count before plugging in.
Setting the checkweighing limits
The procedure below is for the Jadever JWL scale and the JWI-700W indicator. It applies in the same form to the JCL, JCE and JWE scales and the JWI-700C indicator.
Where this pays off
Filling, portioning and pack-checking lines, where the operator handles product with both hands and cannot keep glancing at a display. The buzzer output on the Alarm pin covers the case where the lamp is out of the operator’s line of sight.
Integration note
KALA Technical Notes
The relay outputs switch a signal, not a load — driving a tower directly off them without checking the current rating is how the board gets damaged. Tell us the scale model and the tower you intend to use, and we will confirm whether it needs an interposing relay.
● Checkweighing scales, relay interface boards and signal towers.