diff --git a/core/detectors/trd/CbmTrdParSetAsic.h b/core/detectors/trd/CbmTrdParSetAsic.h
index e5171565d81bfa42f45f63a2606900e0cb506c43..97bce9aed208739b6165579ab8726b8cc7e70a80 100644
--- a/core/detectors/trd/CbmTrdParSetAsic.h
+++ b/core/detectors/trd/CbmTrdParSetAsic.h
@@ -39,7 +39,8 @@ public:
 
   /** \brief Search for the module in the setup parameters by equipement id 
    * \param[in] eqid equipment id from HW
-   * \param[out] crob_id index of crob on the module
+   * \param[out] crob_id index of the ROB (crob in legacy mode) on the module
+   * \param[out] lnk_id index of optical link on the ROB (not used in legacy mode); 0 for down, 1 for up  
    * \return module id in the setup
    */
   virtual int FindModuleByEqId(uint16_t eqid, uint8_t& crob_id, uint8_t& lnk_id) const;