diff --git a/PSSS-PID-check.md b/PSSS-PID-check.md
index 29ba69f..bfa1a56 100644
--- a/PSSS-PID-check.md
+++ b/PSSS-PID-check.md
@@ -4,4 +4,15 @@ An LED installed in front of the PSSS camera which runs a sequence (not currentl
 
 - on: `caput SGE-CPCW-73-EVR0:FrontUnivOut0-Ena-SP 1`
 - off: `caput SGE-CPCW-73-EVR0:FrontUnivOut0-Ena-SP 0`
-![image](uploads/a2830096617e94faa61abf7c38148723/image.png)
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+![image](uploads/a2830096617e94faa61abf7c38148723/image.png)
+
+## Testing pulseID offset/error
+
+Compare bs stream using Edwin's tool
+### Step 1
+Check channel `SARFE10-PSSS059:SPECTRUM_Y_SUM` is in the stream setup
+![image](uploads/3217042a3a8660550765c66279e88dce/image.png)
+### Step 2
+Start stream, and go to data arrival channel.  Check sub channel 1 is 10 Hz(103) and sub channel 2 is the channel under test, i.e SARFE10-PSSS059:SPECTRUM_Y_SUM
+
+<img src="https://docs.google.com/drawings/d/e/2PACX-1vQHUO_lB4PzkU70kxqxcUTBtFcjTqMay4Ls2ObXasLnUPmegB2KYRqsrSYySRlVgPdtjo5JTbSPNKtV/pub?w=929&amp;h=441">
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