From 9d1d753e3f0133f0d0a0826d90654eed165a1d1d Mon Sep 17 00:00:00 2001
From: David Schledt <schledt@iri.uni-frankfurt.de>
Date: Wed, 29 Jun 2022 14:54:19 +0000
Subject: [PATCH] Fix for overflow counting issue in trd1d timing
---
reco/detectors/trd/unpack/CbmTrdUnpackAlgoR.cxx | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/reco/detectors/trd/unpack/CbmTrdUnpackAlgoR.cxx b/reco/detectors/trd/unpack/CbmTrdUnpackAlgoR.cxx
index 6ef532fba2..9292be3990 100644
--- a/reco/detectors/trd/unpack/CbmTrdUnpackAlgoR.cxx
+++ b/reco/detectors/trd/unpack/CbmTrdUnpackAlgoR.cxx
@@ -246,6 +246,8 @@ Spadic::MsMessageType CbmTrdUnpackAlgoR::getMessageType(const std::uint32_t fram
// ---- getTsMsb ----
std::uint8_t CbmTrdUnpackAlgoR::getTsMsb(const std::uint32_t frame)
{
+ if ((frame & 0xf) > 0)
+ return -2; // if a 'error' ts_msb is received the tsmsb value is not correct. To not mess up the counting -2 is returned.
// The epoch in form of the TS_MSBs is written 3 times into the frame to allow to check for bit flips and catch errors. It has the length of 6 bits and an offset of 4
std::uint8_t tsmsb[3];
for (uint iepoch = 0; iepoch < 3; ++iepoch) {
@@ -381,7 +383,7 @@ bool CbmTrdUnpackAlgoR::unpack(const fles::Timeslice* ts, std::uint16_t icomp, U
switch (kWordtype) {
case Spadic::MsMessageType::kEPO: {
auto tsmsb = getTsMsb(frame);
- if (tsmsb > currTsMsb) fNrTsMsbVec.at(istream)++;
+ if (((tsmsb - currTsMsb) & 0x3f) == 1 || currTsMsb == -1) fNrTsMsbVec.at(istream)++;
currTsMsb = tsmsb;
fNrEpochMsgs++;
break;
--
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