Threw together a simple Telnet driver you might be able use to test with:
Driver Code
/*
*/
@SuppressWarnings('unused')
static String version() {return "0.0.0"}
metadata {
definition (
name: "Telnet Test",
namespace: "thebearmay",
author: "Jean P. May, Jr.",
importUrl:"https://raw.githubusercontent.com/thebearmay/hubitat/main/xxxx.groovy"
) {
capability "Telnet"
command "connectTelnet"
command "disconnectTelnet"
}
}
preferences {
input(name: "ipAddr", type: "string", title:"IP Address", required: true)
input(name: "portNum", type: "number", title: "Port Number", required: true)
}
@SuppressWarnings('unused')
def installed() {
}
void updateAttr(String aKey, aValue, String aUnit = ""){
sendEvent(name:aKey, value:aValue, unit:aUnit)
}
def connectTelnet(){
try{
telnetConnect([termChars:[10]], ipAddr, (int)portNum, null, null)
} catch (ex) {
updateAttr("error", ex)
}
}
def disconnectTelnet() {
telnetClose()
}
def sendMsg(message) {
sendHubCommand(new hubitat.device.HubAction("""$message\r\n""", hubitat.device.Protocol.TELNET))
}
def parse(message) {
updateAttr("parsedMessage", message)
}
def telnetStatus(message){
updateAttr("statusMessage", message)
}
Messages returned are not retained by the driver, but will display on the device page. Enter the IP address and port number, click on connect, and then type the command (-p 1, -p 0, etc) in the Send Message box and click it to send. Click disconnect when done.