View difference between Paste ID: H3G51hyU and FvJawsAi

 local channel = 0
 local modem
 
 
 function setModem(side)
     modem = peripheral.wrap(side)
 end
 
 function setChannel(ch)
     channel = ch
 end
 
 function openModem(ch)
     ch = ch or channel
     if not modem.isOpen(ch) then
         modem.open(ch)
         print("Opened modem: " .. ch)
     else
         print("Modem already opened: " .. ch)
     end
 end
 
 function closeModem(ch)
     ch = ch or channel
     if modem.isOpen(ch) then
         modem.close(ch)
         print("Closed modem: " .. ch)
     else
         print("Modem already closed: " .. ch)
     end
 end
 
 function modemSetup(side, ch)
     modem = peripheral.wrap(side)
     setChannel(ch)
     openModem()
 end
 
 function sendMessage(msg, ch, returnCh)
     ch = ch or channel
     returnCh = returnCh or channel
 
     if type(msg) == "table" then
         msg = textutils.serialize(msg)
     end
 
     modem.transmit(ch, returnCh, msg)
 end
 
 
 function waitForMessage(ch, timeout)
     ch = ch or channel
     local myTimer
     if timeout then
         myTimer = os.startTimer(timeout)
     end
     while true do
         local event, par1, senderChannel,
         replyChannel, message, senderDistance = os.pullEvent()
 
         if event == "timer" and par1 == myTimer then
             print("message timeout")
             return false
         end
 
         if senderChannel == ch then
             return true, message, replyChannel
         end
     end
 end
 
 function sendAndWaitForResponse(msg, ch, returnCh, timeout)
     sendMessage(msg, ch, returnCh)
 
     local worked, message, replyChannel = waitForMessage(returnCh, timeout)
     return worked, message, replyChannel
 end