diff --git a/occ_presence.cpp b/occ_presence.cpp
new file mode 100644
index 0000000..f91521a
--- /dev/null
+++ b/occ_presence.cpp
@@ -0,0 +1,57 @@
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <phosphor-logging/log.hpp>
+#include <phosphor-logging/elog.hpp>
+#include <xyz/openbmc_project/Common/error.hpp>
+#include <org/open_power/OCC/Device/error.hpp>
+#include "occ_presence.hpp"
+#include "occ_manager.hpp"
+#include "elog-errors.hpp"
+
+namespace open_power
+{
+namespace occ
+{
+
+// Reads the occs_present file and analyzes the data
+void Presence::analyzeEvent()
+{
+    using namespace phosphor::logging;
+    using namespace sdbusplus::org::open_power::OCC::Device::Error;
+
+    // Get the number of bytes to read
+    int len = -1;
+    auto r = ioctl(fd, FIONREAD, &len);
+    if (r < 0)
+    {
+        elog<ConfigFailure>(
+            phosphor::logging::org::open_power::OCC::Device::
+                ConfigFailure::CALLOUT_ERRNO(errno),
+            phosphor::logging::org::open_power::OCC::Device::
+                ConfigFailure::CALLOUT_DEVICE_PATH(file.c_str()));
+    }
+
+    auto data = readFile(len);
+    if (data.empty())
+    {
+        return;
+    }
+
+    // Let stoi determine the base
+    auto occsPresent = std::stoi(data, nullptr, 0);
+    if (manager.getNumOCCs() != occsPresent)
+    {
+        log<level::INFO>("OCC presence mismatch",
+                         entry("BMC_OCCS=%d", manager.getNumOCCs(),
+                         entry("OCC_OCCS=%d", occsPresent)));
+        if (callBack)
+        {
+            callBack();
+        }
+    }
+}
+
+} // namespace occ
+} // namespace open_power