diff --git a/tests/common/mod.rs b/tests/common/mod.rs
index f56ef15..74d3b20 100644
--- a/tests/common/mod.rs
+++ b/tests/common/mod.rs
@@ -197,6 +197,37 @@ assertion failed: `(left[{}] == right[{}])`
     }
 }
 
+#[macro_export]
+macro_rules! assert_decimated_slope_feq_sfine {
+    ($vec:expr, $decimate:expr, $cmp_vec:expr) => {
+        let cmp_vec = $cmp_vec;
+        let mut res : Vec<f32> = vec![];
+        let mut prev = 0.0;
+        for (i, s) in $vec.iter().enumerate() {
+            let delta = *s - prev;
+            if i > 0 {
+                res.push(delta);
+            }
+            prev = *s;
+        }
+
+        let res : Vec<f32> = res.iter().step_by($decimate).copied().collect();
+
+        for (i, (s, scmp)) in res.iter().zip(cmp_vec.iter()).enumerate() {
+            if (s - scmp).abs() > 0.000000001 {
+                panic!(r#"
+table_left: {:?}
+
+table_right: {:?}
+
+assertion failed: `(left[{}] == right[{}])`
+      left: `{:?}`,
+     right: `{:?}`"#, &res[i..], &(cmp_vec[i..]), i, i, s, scmp)
+            }
+        }
+    }
+}
+
 #[allow(dead_code)]
 pub fn collect_signal_changes(inp: &[f32], thres: i64) -> Vec<(usize, i64)> {
     let mut idxs = vec![];
diff --git a/tests/node_tslfo.rs b/tests/node_tslfo.rs
new file mode 100644
index 0000000..6fa16d8
--- /dev/null
+++ b/tests/node_tslfo.rs
@@ -0,0 +1,100 @@
+// Copyright (c) 2021 Weird Constructor <weirdconstructor@gmail.com>
+// This file is a part of HexoDSP. Released under GPL-3.0-or-later.
+// See README.md and COPYING for details.
+
+mod common;
+use common::*;
+
+#[test]
+fn check_node_tslfo_1() {
+    let (node_conf, mut node_exec) = new_node_engine();
+    let mut matrix = Matrix::new(node_conf, 3, 3);
+
+    let tsl = NodeId::TsLfo(0);
+    let out = NodeId::Out(0);
+    matrix.place(0, 0, Cell::empty(tsl)
+                       .out(None, None, tsl.out("sig")));
+    matrix.place(0, 1, Cell::empty(out)
+                       .input(out.inp("ch1"), None, None));
+    pset_d(&mut matrix, tsl, "time", 0.1);
+    matrix.sync().unwrap();
+
+    // Test shortest time 0.1ms:
+    let (out_l, _) = run_for_ms(&mut node_exec, 1.0);
+    assert_decimated_feq!(out_l, 1, vec![
+        0.0, 0.4535, 0.9070, 0.6394, 0.1859,
+        0.2675, 0.7210, 0.8253, 0.37188, 0.0816
+    ]);
+
+    // Test 1ms:
+    pset_d_wait(&mut matrix, &mut node_exec, tsl, "time", 1.0);
+    let (out_l, _) = run_for_ms(&mut node_exec, 5.0);
+    assert_decimated_feq!(out_l, 10, vec![
+        0.7103, 0.8361,
+        0.3826, 0.0708, 0.5244, 0.9779, 0.5685, 0.1150,
+        0.3384
+    ]);
+
+    // Test 300000.0 ms
+    pset_d_wait(&mut matrix, &mut node_exec, tsl, "time", 300000.0);
+    let (out_l, _) = run_for_ms(&mut node_exec, 3000.0);
+    let ramp_slope = 1.0_f64 / (300.0 * 44100.0);
+    let tri_slope = ramp_slope * 2.0;
+    assert_float_eq!(
+        (out_l[0] - out_l[10000]).abs(),
+        (tri_slope * 10000.0) as f32);
+    assert_float_eq!(
+        (out_l[10000] - out_l[11000]).abs(),
+        (tri_slope * 1000.0) as f32);
+    assert_decimated_feq!(out_l, 10000, vec![
+        0.7566, // => Slope is ~0.0015 per 10000 samples
+        0.7551,
+        0.7536,
+        0.7521,
+        0.7506,
+        0.7490,
+        0.7475,
+    ]);
+}
+
+#[test]
+fn check_node_tslfo_trig_slopes() {
+    let (node_conf, mut node_exec) = new_node_engine();
+    let mut matrix = Matrix::new(node_conf, 3, 3);
+
+    let tsl = NodeId::TsLfo(0);
+    let out = NodeId::Out(0);
+    matrix.place(0, 0, Cell::empty(tsl)
+                       .out(None, None, tsl.out("sig")));
+    matrix.place(0, 1, Cell::empty(out)
+                       .input(out.inp("ch1"), None, None));
+    matrix.sync().unwrap();
+
+    // Test 1ms but at full ramp up and resync/trigger:
+    pset_d(&mut matrix, tsl, "rev", 1.0);
+    pset_d_wait(&mut matrix, &mut node_exec, tsl, "time", 10.0);
+    pset_d_wait(&mut matrix, &mut node_exec, tsl, "trig", 1.0);
+    let (out_l, _) = run_for_ms(&mut node_exec, 15.0);
+    let ramp_slope = 1.0_f64 / ((10.0 / 1000.0) * 44100.0);
+    assert_float_eq!(
+        (out_l[0] - out_l[1]).abs(),
+        ramp_slope as f32);
+    assert_decimated_feq!(out_l, 50, vec![
+        0.7513184, 0.8648106, 0.9783028, 0.09079399, 0.20428619, 0.3177784
+    ]);
+
+    pset_d_wait(&mut matrix, &mut node_exec, tsl, "trig", 0.0);
+
+    // Test 1ms but at full ramp down and resync/trigger:
+    pset_d(&mut matrix, tsl, "rev", 0.0);
+    pset_d_wait(&mut matrix, &mut node_exec, tsl, "time", 10.0);
+    pset_d_wait(&mut matrix, &mut node_exec, tsl, "trig", 1.0);
+    let (out_l, _) = run_for_ms(&mut node_exec, 15.0);
+    let ramp_slope = 1.0_f64 / ((10.0 / 1000.0) * 44100.0);
+    assert_float_eq!(
+        (out_l[0] - out_l[1]).abs(),
+        ramp_slope as f32);
+    assert_decimated_feq!(out_l, 50, vec![
+        0.24945788, 0.13606784, 0.022677781, 0.90938777, 0.7959977
+    ]);
+}