diff --git a/config/devices.properties b/config/devices.properties
index e638841..1adbf78 100644
--- a/config/devices.properties
+++ b/config/devices.properties
@@ -1,4 +1,4 @@
 robot=RobotTcp|127.0.0.1:1000|||
-robot_modbus=RobotModbus|gac-S_Changer|||
+robot_modbus=RobotModbus|gac-S_Changer:502|||
 $dewar=ch.psi.pshell.modbus.ModbusTCP|127.0.0.1|||
 $temperature=ch.psi.pshell.modbus.AnalogInput|dewar 0|||