diff --git a/Cargo.lock b/Cargo.lock
index 67a753b..7059da2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 4
+version = 3
 
 [[package]]
 name = "aho-corasick"
@@ -165,9 +165,9 @@ checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"
 
 [[package]]
 name = "libc"
-version = "0.2.169"
+version = "0.2.162"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5aba8db14291edd000dfcc4d620c7ebfb122c613afb886ca8803fa4e128a20a"
+checksum = "18d287de67fe55fd7e1581fe933d965a5a9477b38e949cfa9f8574ef01506398"
 
 [[package]]
 name = "libudev"
@@ -235,18 +235,17 @@ checksum = "953ec861398dccce10c670dfeaf3ec4911ca479e9c02154b3a215178c5f566f2"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.92"
+version = "1.0.89"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37d3544b3f2748c54e147655edb5025752e2303145b5aefb3c3ea2c78b973bb0"
+checksum = "f139b0662de085916d1fb67d2b4169d1addddda1919e696f3252b740b629986e"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "profirust"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "47e1ffcf51ad3251d763ff97e64a94ec8ccd6af5a165e1a8a962804e2d64731a"
+version = "0.4.0"
+source = "git+https://github.com/rahix/profirust.git?rev=1a02cb771426ffdd4d88cdbfd163a7f2148a7c83#1a02cb771426ffdd4d88cdbfd163a7f2148a7c83"
 dependencies = [
  "bitflags 2.6.0",
  "bitvec",
@@ -307,9 +306,9 @@ checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
 [[package]]
 name = "serialport"
-version = "4.6.1"
+version = "4.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "779e2977f0cc2ff39708fef48f96f3768ac8ddd8c6caaaab82e83bd240ef99b2"
+checksum = "7331eefcaafaa382c0df95bcd84068f0b3e3c215c300750dde2316e9b8806ed5"
 dependencies = [
  "bitflags 2.6.0",
  "cfg-if",
@@ -326,9 +325,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.90"
+version = "2.0.87"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "919d3b74a5dd0ccd15aeb8f93e7006bd9e14c295087c9896a110f490752bcf31"
+checksum = "25aa4ce346d03a6dcd68dd8b4010bcb74e54e62c90c573f394c46eae99aba32d"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -372,9 +371,9 @@ dependencies = [
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.14"
+version = "1.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "adb9e6ca4f869e1180728b7950e35922a7fc6397f7b641499e8f3ef06e50dc83"
+checksum = "e91b56cd4cadaeb79bbf1a5645f6b4f8dc5bde8834ad5894a8db35fda9efa1fe"
 
 [[package]]
 name = "utf8parse"
diff --git a/Cargo.toml b/Cargo.toml
index a34d67d..5ee3427 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,6 +8,8 @@ env_logger = "0.11.5"
 log = "0.4.22"
 
 [dependencies.profirust]
-version = "0.5.0"
+version = "0.4.0"
 default-features = false
 features = ["phy-serial", "std"]
+rev = "1a02cb771426ffdd4d88cdbfd163a7f2148a7c83"
+git = "https://github.com/rahix/profirust.git"
diff --git a/src/main.rs b/src/main.rs
index 4e6276b..9473a75 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,12 +5,10 @@ use profirust::phy;
 mod tester_io;
 mod valve_terminal;
 
-// Muss auf den passenden USB-RS485 Port abgeändert werden!
-const BUS_DEVICE: &'static str = "/dev/ttyUSB0";
-
 // Bus Parameters
-const MASTER_ADDRESS: u8 = 3;
-const BAUDRATE: profirust::Baudrate = profirust::Baudrate::B500000;
+const MASTER_ADDRESS: u8 = 1;
+const BUS_DEVICE: &'static str = "/dev/ttyUSB0";
+const BAUDRATE: profirust::Baudrate = profirust::Baudrate::B19200;
 
 fn main() -> ! {
     env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info"))
@@ -25,18 +23,19 @@ fn main() -> ! {
     let mut tester_io = tester_io::TesterIo::new(&mut dp_master, BAUDRATE);
     let mut valve_terminal = valve_terminal::ValveTerminal::new(&mut dp_master, BAUDRATE);
 
-    // Bus-Parameter für USB-RS485 Converter sind hier beschrieben: https://docs.rs/profirust/latest/profirust/phy/struct.SerialPortPhy.html
     let mut fdl = fdl::FdlActiveStation::new(
         fdl::ParametersBuilder::new(MASTER_ADDRESS, BAUDRATE)
-            .slot_bits(4000)
-            .max_retry_limit(3)
+            // We use a rather large T_slot time because USB-RS485 converters
+            // can induce large delays at times.
+            .slot_bits(960)
             // 2 Sekunden Watchdog Timeout
             .watchdog_timeout(profirust::time::Duration::from_secs(2))
             .build_verified(&dp_master),
     );
-    let sleep_time = std::time::Duration::from_micros(3500);
+    // We must not poll() too often or to little. T_slot / 2 seems to be a good compromise.
+    let sleep_time: std::time::Duration = (fdl.parameters().slot_time() / 2).into();
 
-    log::info!("Verbindung mit dem Bus {BUS_DEVICE:?} wird aufgebaut...");
+    log::info!("Verbindung mit dem Bus wird aufgebaut...");
     let mut phy = phy::SerialPortPhy::new(BUS_DEVICE, fdl.parameters().baudrate);
 
     fdl.set_online();