Hello, The 34401A is not longer available in Canada. We need to change and use the 34461A as a replacement and we are having trouble with the peak-to-peak measurements (We are using LabVIEW). We use the peak-to-peak option while reading a communication line in order to get the min and max values. The code: Visa Write 34410A CONF:VOLT:AC VOLT:AC:PEAK:STAT ON INIT FETC? Visa Read Visa Write FETC:VOLT:AC:PTP? Visa Read This code no longer works with the 34461A. Reading the AC will only give the RMS values. We dont really care how to get the min-max of the communication channel, as long as it is in a respectable time (10s at most...). Reading the signal with DC is not fast enough. The communication signal is ±100mv. We verify the min-max range to be around 200mV. Thanks