diff --git a/adc_pin_probe.cpp b/adc_pin_probe.cpp
index e67a982..3a4c31d 100644
--- a/adc_pin_probe.cpp
+++ b/adc_pin_probe.cpp
@@ -46,7 +46,7 @@ struct Config {
     double capture_ms = 120.0;
     uint32_t range = X502_ADC_RANGE_5;
     uint32_t top = 8;
-    std::vector<uint32_t> exclude_phy = {2, 3, 18, 19};
+    std::vector<uint32_t> exclude_phy;
 
     uint32_t recv_block_words = 8192;
     uint32_t recv_timeout_ms = 50;
@@ -214,7 +214,7 @@ void print_help(const char* exe_name) {
         << "  capture_ms:120\n"
         << "  range:5           -> +/-5 V\n"
         << "  top:8\n"
-        << "  exclude_phy:2,3,18,19  -> excludes X3,Y3,X4,Y4 from current diff setup\n"
+        << "  exclude_phy:none  -> scan all channels 0..31 (including 2,3,18,19)\n"
         << "\n"
         << "Single-ended physical channel mapping:\n"
         << "  0..15  -> X1..X16\n"