[RC232] When the MAC layer has a packet to send, it will use a carrier-sense-multiple-access (CSMA) protocol to determine if another module is already transmitting. If another module is transmitting, the module will receive that data before attempting to transmit its data again. If, during this process, the UART receive buffer gets full, the CTS line will go high to prevent the host UART from over-running the receive buffer. The CSMA mechanism introduces a variable delay to the transmission channel. This delay is the sum of a random period and a weighted period that is dependent on the number of times that the module has tried and failed to acquire the channel. For applications that guarantee that only one module will be transmitting at any given time, the CSMA mechanism can be turned off to avoid this delay.

[RC232] “When I connect to the development board using your software (“”RC232 Configuration and Communication Tool””), everything works fine. But when I connect to the development board from inside my own application for the first time each day (e.g. in the morning when the dev. boards have been powered down for a couple of hours), it only sends 0x00s via the air interface, no matter what i want to send, everything is zero. When I then connect to the board once with your software, everything works fine again and also my application afterwards works fine, and I can send everything correctly again. But I have to do this every morning again. Maybe you have any ideas what the reason for this is or what I could do to fix this problem? “

[RC232] “We are drawing a new board which used your module RC1180. We are in a final phase. For the interface with the our µC, we connected only the pins : – RxD & TxD for module configuration and normal use for communication – Pin Reset, Pin 19, Pin 20 : for future programming (case of firmware update) Also, we connected the pin Vcc and ground with recommandations described in your data sheet. I would like to know, if we can use functions of test carrier transmit, modulation transmit and permanent receipt with only the pins RxD and TxD (RTS, CTS and config not connected to our µC but available on test pads). Do you have a procedure to put this module in test mode. For a firmware upgrade, could you confirm us that we need only Pin 19, 20 and reset ? “

[RC232] “we are building an application with one master boat, which communicates with 150 slaves boats (obviously in open sea). Each slave boat will have a bit rate of 1Kbps to the master boat, the signal range must be till 2km. We are considering using RC17xxHP-RC232 modules to communicate with master boat and slaves. Our questions are: It will be the RC1780HP-RC232 module suitable for this application, or you propose some other module? It’s possible with this device to create a multipoint network (one master, many slaves)? Does your modules have frequency hopping function? “

[RC232] “I have problem to wake up RS1240 from sleep mode, in fact I can’t wake it up at all. According to documentation, config pin should be asserted when going to sleep mode, and then positive edge should wake ip module This is code I use: Config Portd.3 = Output : Modem_config Alias Portd.3 Modem_config = 1 ‘ ———— PUT MODEM IN SLEEP MODE Modem_config = 0 ‘ Assert Config pin Waitms 5 ‘ MAX Time from CONFIG pin is set low until prompt (“”>””) Print “”Z””; ‘ Goto SLEEP mode . . . Sub Send_packet Modem_config = 1 ‘ Wake up form SLEEP mode Waitms 60 ‘ Wait 60 ms to get out from sleep mode Print “”X””; ‘ Goto idle mode Led_tx = 1 Printbin Paket_start Printbin Data_packet Led_tx = 0 Modem_config = 0 ‘ Assert Config PIN Waitms 5 ‘ MAX Time from CONFIG pin is set low until prompt (“”>””) Print “”Z””; ‘ SLEEP mode End Sub But, module stuck in sleep mode, and dont send enything. When I comment all lines regarding sleep mode, module work fine. Where I’m wrong? I should deliver device this week, and this is only problem I have to resolve. “