diff --git a/lmwsip/__init__.py b/lmwsip/__init__.py
index d2d6b3e..a225a22 100644
--- a/lmwsip/__init__.py
+++ b/lmwsip/__init__.py
@@ -25,6 +25,468 @@ Support for:
     cmd(wn, vw, as)
 
 """
+    lmwParameters = {
+        'Tm02_MV': ('VW', 1, 0),
+        'xH1': ('WN', 1, 1),
+        'HH1S': ('WN', 1, 1),
+        'SRV1': ('WN', 1, 1),
+        'TL1': ('WN', 1, 1),
+        'SRV1w1': ('WN', 1, 1),
+        'SRV1w2': ('WN', 1, 1),
+        'SRV1w3': ('WN', 1, 1),
+        'xTL1': ('WN', 1, 1),
+        'DO1': ('WN', 1, 1),
+        'SSV1': ('WN', 1, 1),
+        'SSV1w3G': ('WN', 1, 1),
+        'SSV1w3': ('WN', 1, 1),
+        'SSV1w2G': ('WN', 1, 1),
+        'SSV1w2': ('WN', 1, 1),
+        'SSV1w1G': ('WN', 1, 1),
+        'H1Z': ('WN', 1, 1),
+        'SSV1w1': ('WN', 1, 1),
+        'H1': ('WN', 1, 1),
+        'bSSVG1': ('WN', 1, 1),
+        'xWS1': ('WN', 1, 1),
+        'HG1Z': ('WN', 1, 1),
+        'WS1': ('WN', 1, 1),
+        'HG1': ('WN', 1, 1),
+        'WR1': ('WN', 1, 1),
+        'ZA1': ('WN', 1, 1),
+        'ZM1': ('WN', 1, 1),
+        'H1RC': ('WN', 1, 1),
+        'bSRV1': ('WN', 1, 1),
+        'bSSV1': ('WN', 1, 1),
+        'xWR1': ('WN', 1, 1),
+        'THmax': ('WN', 1, 10),
+        'Th0_B4': ('WN', 1, 10),
+        'Th0': ('WN', 1, 10),
+        'Th0_G1': ('WN', 1, 10),
+        'Th0_B3': ('WN', 1, 10),
+        'Th0_G10': ('WN', 1, 10),
+        'Th010': ('WN', 51, 10),
+        'Th0_G7': ('WN', 1, 10),
+        'Th0_B0': ('WN', 1, 10),
+        'Th0_G6': ('WN', 1, 10),
+        'Th0_G2': ('WN', 1, 10),
+        'Th0_G3': ('WN', 1, 10),
+        'Th0_B2': ('WN', 1, 10),
+        'Th0_B1': ('WN', 1, 10),
+        'Th0_G5': ('WN', 1, 10),
+        'Th0_G4': ('WN', 1, 10),
+        'Th0_G8': ('WN', 1, 10),
+        'Th0_G9': ('WN', 1, 10),
+        'TW10S': ('WN', 1, 10),
+        'U10': ('WN', 1, 10),
+        'UUR10': ('WN', 1, 10),
+        'Th3V': ('VW', 1, 10),
+        'V10': ('WN', 1, 10),
+        'V10S': ('WN', 1, 10),
+        'WC10': ('WN', 1, 10),
+        'WC10MXS3': ('WN', 1, 10),
+        'WC10V': ('VW', 1, 10),
+        'TW10': ('WN', 1, 10),
+        'Tm_10_M': ('WN', 1, 10),
+        'Tmax': ('WN', 1, 10),
+        'Th3': ('WN', 1, 10),
+        'Tm_10': ('WN', 1, 10),
+        'TL10': ('WN', 1, 10),
+        'TL10MNM1': ('WN', 1, 10),
+        'TL10MXM1': ('WN', 1, 10),
+        'Tm02': ('WN', 1, 10),
+        'Tm02V': ('VW', 1, 10),
+        'Tm02V_M': ('VW', 1, 10),
+        'Tm02_M': ('WN', 1, 10),
+        'WDG10': ('WN', 1, 10),
+        'TH1d3': ('WN', 1, 10),
+        'S0bh_G10': ('WN', 1, 10),
+        'SPGH': ('WN', 1, 10),
+        'SPGT': ('WN', 1, 10),
+        'SRV10': ('WN', 1, 10),
+        'SRV10m': ('WN', 50, 10),
+        'SRV10STD': ('WN', 1, 10),
+        'SRV10V': ('VW', 1, 10),
+        'SRV10w1': ('WN', 1, 10),
+        'SRV10w2': ('WN', 1, 10),
+        'SRV10w3': ('WN', 1, 10),
+        'SS10': ('WN', 1, 10),
+        'SH10': ('WN', 1, 10),
+        'SG10': ('WN', 1, 10),
+        'SEC10': ('WN', 1, 10),
+        'S0bh_G2': ('WN', 1, 10),
+        'S0bh_G3': ('WN', 1, 10),
+        'S0bh_G4': ('WN', 1, 10),
+        'S0bh_G5': ('WN', 1, 10),
+        'S0bh_G6': ('WN', 1, 10),
+        'S0bh_G7': ('WN', 1, 10),
+        'S0bh_G8': ('WN', 1, 10),
+        'S0bh_G9': ('WN', 1, 10),
+        'SAL10': ('WN', 1, 10),
+        'SD10': ('WN', 1, 10),
+        'SSG10': ('WN', 1, 10),
+        'SSV10': ('WN', 1, 10),
+        'SSV10A': ('AS', 1, 10),
+        'T10': ('WN', 1, 10),
+        'T1d3': ('WN', 1, 10),
+        'T1d3V': ('VW', 1, 10),
+        'TD10': ('WN', 1, 10),
+        'TD10M1': ('WN', 1, 10),
+        'TE0': ('WN', 1, 10),
+        'TE1': ('WN', 1, 10),
+        'TE1_M': ('WN', 1, 10),
+        'TE2': ('WN', 1, 10),
+        'TE3': ('WN', 1, 10),
+        'Stat10Sm': ('WN', 50, 10),
+        'Stat10S': ('WN', 1, 10),
+        'ST10': ('WN', 1, 10),
+        'SSV10m': ('WN', 50, 10),
+        'SSV10V': ('VW', 1, 10),
+        'SSV10w1': ('WN', 1, 10),
+        'SSV10w1G': ('WN', 1, 10),
+        'SSV10w2': ('WN', 1, 10),
+        'SSV10w2G': ('WN', 1, 10),
+        'SSV10w3': ('WN', 1, 10),
+        'SSV10w3G': ('WN', 1, 10),
+        'SSVG10': ('WN', 1, 10),
+        'SSVG10V': ('VW', 1, 10),
+        'TE3V': ('VW', 1, 10),
+        'xP10': ('WN', 1, 10),
+        'xSS10': ('WN', 1, 10),
+        'xSSV10': ('WN', 1, 10),
+        'xT1d3': ('WN', 1, 10),
+        'xTD10': ('WN', 1, 10),
+        'xTD10M1': ('WN', 1, 10),
+        'xTE1': ('WN', 1, 10),
+        'xTE2': ('WN', 1, 10),
+        'xTE3': ('WN', 1, 10),
+        'xTH1d3': ('WN', 1, 10),
+        'xTHmax': ('WN', 1, 10),
+        'xTh0': ('WN', 1, 10),
+        'xSRV10': ('WN', 1, 10),
+        'xSPGT': ('WN', 1, 10),
+        'xSPGH': ('WN', 1, 10),
+        'xPC10': ('WN', 1, 10),
+        'xPH': ('WN', 1, 10),
+        'xPH10': ('WN', 1, 10),
+        'xPQFE10': ('WN', 1, 10),
+        'xPQFF10': ('WN', 1, 10),
+        'xPQNH10': ('WN', 1, 10),
+        'xQ10': ('WN', 1, 10),
+        'xQ10B': ('VW', 1, 10),
+        'xR10': ('WN', 1, 10),
+        'xRS10': ('WN', 1, 10),
+        'xSH10P': ('WN', 1, 10),
+        'xTh3': ('WN', 1, 10),
+        'xTL10': ('WN', 1, 10),
+        'xWR10': ('WN', 1, 10),
+        'xWR10STD': ('WN', 1, 10),
+        'xWS10': ('WN', 1, 10),
+        'xWS10MX': ('WN', 1, 10),
+        'xWS10MXS': ('WN', 1, 10),
+        'xWS10STD': ('WN', 1, 10),
+        'xWS10XS1': ('WN', 1, 10),
+        'xZM10': ('WN', 1, 10),
+        'ZA10': ('WN', 1, 10),
+        'ZM10': ('WN', 1, 10),
+        'ZMT10': ('WN', 1, 10),
+        'xWC10MXS': ('WN', 1, 10),
+        'xWC10': ('WN', 1, 10),
+        'xVE10s': ('WN', 1, 10),
+        'xTL10MNM': ('WN', 1, 10),
+        'xTL10MXM': ('WN', 1, 10),
+        'xTm02': ('WN', 1, 10),
+        'xTmax': ('WN', 1, 10),
+        'xTm_10': ('WN', 1, 10),
+        'xTT10P': ('WN', 1, 10),
+        'xTW10': ('WN', 1, 10),
+        'xU10': ('WN', 1, 10),
+        'xV10': ('WN', 1, 10),
+        'xVE10': ('WN', 1, 10),
+        'xVE10S': ('WN', 1, 10),
+        'ZV10S': ('WN', 1, 10),
+        'WI': ('BL', 8, 10),
+        'xBS10S': ('WN', 1, 10),
+        'xBS10s': ('WN', 1, 10),
+        'xC10P': ('WN', 1, 10),
+        'xCHL10': ('WN', 1, 10),
+        'xCL10': ('WN', 1, 10),
+        'xCzz10': ('WN', 51, 10),
+        'xCzz5': ('WN', 25, 10),
+        'xD10': ('WN', 1, 10),
+        'xDO10': ('WN', 1, 10),
+        'xDO10P': ('WN', 1, 10),
+        'xFp': ('WN', 1, 10),
+        'xBM10s': ('WN', 1, 10),
+        'xBM10S': ('WN', 1, 10),
+        'xAV10_H': ('WN', 1, 10),
+        'WNR10': ('WN', 1, 10),
+        'WR10': ('WN', 1, 10),
+        'WR10STD': ('WN', 1, 10),
+        'WR10V': ('VW', 1, 10),
+        'WS10': ('WN', 1, 10),
+        'WS10MX10': ('WN', 1, 10),
+        'WS10MXS3': ('WN', 1, 10),
+        'WS10STD': ('WN', 1, 10),
+        'WS10V': ('VW', 1, 10),
+        'xAG': ('WN', 1, 10),
+        'xANT10': ('WN', 1, 10),
+        'xGE10': ('WN', 1, 10),
+        'xGGH': ('WN', 1, 10),
+        'xHS7': ('WN', 1, 10),
+        'xHTE3': ('WN', 1, 10),
+        'xKH10B': ('VW', 1, 10),
+        'xM0': ('WN', 1, 10),
+        'xNdlr_H': ('WN', 1, 10),
+        'xNd_z': ('WN', 1, 10),
+        'xNgd_zP': ('WN', 1, 10),
+        'xNI10': ('WN', 1, 10),
+        'xNi_z': ('WN', 1, 10),
+        'xNu_z': ('WN', 1, 10),
+        'xNv_z': ('WN', 1, 10),
+        'xHmax': ('WN', 1, 10),
+        'xHm0': ('WN', 1, 10),
+        'xHHR10': ('WN', 1, 10),
+        'xGGT': ('WN', 1, 10),
+        'xH10': ('WN', 1, 10),
+        'xH10BV': ('VW', 1, 10),
+        'xH10R': ('WN', 1, 10),
+        'xH10Z': ('WN', 1, 10),
+        'xH1d10': ('WN', 1, 10),
+        'xH1d3': ('WN', 1, 10),
+        'xH1d50': ('WN', 1, 10),
+        'xHCM': ('WN', 1, 10),
+        'xHH10': ('WN', 1, 10),
+        'xHH10R': ('WN', 1, 10),
+        'xNwt_zP': ('WN', 1, 10),
+        'G1_B0': ('WN', 1, 10),
+        'G2_B0': ('WN', 1, 10),
+        'G2_B1': ('WN', 1, 10),
+        'G2_B2': ('WN', 1, 10),
+        'G2_B3': ('WN', 1, 10),
+        'G2_B4': ('WN', 1, 10),
+        'G2_G1': ('WN', 1, 10),
+        'G2_G10': ('WN', 1, 10),
+        'G2_G2': ('WN', 1, 10),
+        'G2_G3': ('WN', 1, 10),
+        'G2_G4': ('WN', 1, 10),
+        'G2_G5': ('WN', 1, 10),
+        'G1_G9': ('WN', 1, 10),
+        'G1_G8': ('WN', 1, 10),
+        'G1_G7': ('WN', 1, 10),
+        'G1_B1': ('WN', 1, 10),
+        'G1_B2': ('WN', 1, 10),
+        'G1_B3': ('WN', 1, 10),
+        'G1_B4': ('WN', 1, 10),
+        'G1_G1': ('WN', 1, 10),
+        'G1_G10': ('WN', 1, 10),
+        'G1_G2': ('WN', 1, 10),
+        'G1_G3': ('WN', 1, 10),
+        'G1_G4': ('WN', 1, 10),
+        'G1_G5': ('WN', 1, 10),
+        'G1_G6': ('WN', 1, 10),
+        'G2_G6': ('WN', 1, 10),
+        'G2_G7': ('WN', 1, 10),
+        'G2_G8': ('WN', 1, 10),
+        'GK': ('BL', 11, 10),
+        'GKZ': ('BL', 11, 10),
+        'GO': ('BL', 70, 10),
+        'GO_H': ('BL', 35, 10),
+        'GO_L': ('BL', 35, 10),
+        'GR': ('BL', 107, 10),
+        'GRZ': ('BL', 107, 10),
+        'GW': ('BL', 6, 10),
+        'H10': ('WN', 1, 10),
+        'H10A': ('AS', 1, 10),
+        'H10RC': ('WN', 1, 10),
+        'GH_M': ('BL', 27, 10),
+        'GHZ': ('BL', 128, 10),
+        'GHRZ': ('BL', 78, 10),
+        'G2_G9': ('WN', 1, 10),
+        'GB': ('BL', 35, 10),
+        'GE10': ('WN', 1, 10),
+        'GE10S': ('WN', 1, 10),
+        'GGH': ('WN', 1, 10),
+        'GGT': ('WN', 1, 10),
+        'GH': ('BL', 27, 10),
+        'GH2': ('BL', 27, 10),
+        'GHC': ('BL', 76, 10),
+        'GHC_M': ('BL', 126, 10),
+        'GHR': ('BL', 128, 10),
+        'H10V': ('VW', 1, 10),
+        'AB': ('BL', 256, 10),
+        'bSSV10': ('WN', 1, 10),
+        'bSSVG10': ('WN', 1, 10),
+        'C10P': ('WN', 1, 10),
+        'C110S': ('WN', 1, 10),
+        'C210S': ('WN', 1, 10),
+        'C310S': ('WN', 1, 10),
+        'CHL10': ('WN', 1, 10),
+        'CL10': ('WN', 1, 10),
+        'Cor10': ('WN', 1, 10),
+        'Cor10m': ('WN', 50, 10),
+        'CX10S': ('WN', 1, 10),
+        'bSRV10': ('WN', 1, 10),
+        'bQ10': ('WN', 1, 10),
+        'bH10': ('WN', 1, 10),
+        'AG': ('WN', 1, 10),
+        'AL': ('BL', 35, 10),
+        'AV10_H': ('WN', 1, 10),
+        'AV10_R': ('WN', 1, 10),
+        'BCor10': ('WN', 1, 10),
+        'BEcho10': ('WN', 1, 10),
+        'BH10': ('WN', 1, 10),
+        'BNgd10P': ('WN', 1, 10),
+        'BSRV10': ('WN', 1, 10),
+        'BSSV10': ('WN', 1, 10),
+        'BT10': ('WN', 1, 10),
+        'Czz10': ('WN', 51, 10),
+        'Czz10_M': ('WN', 101, 10),
+        'Czz5': ('WN', 25, 10),
+        'Fm01_G1': ('WN', 1, 10),
+        'Fm01_G10': ('WN', 1, 10),
+        'Fm01_G2': ('WN', 1, 10),
+        'Fm01_G3': ('WN', 1, 10),
+        'Fm01_G4': ('WN', 1, 10),
+        'Fm01_G5': ('WN', 1, 10),
+        'Fm01_G6': ('WN', 1, 10),
+        'Fm01_G7': ('WN', 1, 10),
+        'Fm01_G8': ('WN', 1, 10),
+        'Fm01_G9': ('WN', 1, 10),
+        'Fp': ('WN', 1, 10),
+        'Fm01_B4': ('WN', 1, 10),
+        'Fm01_B3': ('WN', 1, 10),
+        'Fm01_B2': ('WN', 1, 10),
+        'D10': ('WN', 1, 10),
+        'D10S': ('WN', 1, 10),
+        'DH10': ('WN', 1, 10),
+        'DL_index': ('WN', 1, 10),
+        'DO10': ('WN', 1, 10),
+        'DO10P': ('WN', 1, 10),
+        'DT10': ('WN', 1, 10),
+        'Echo10': ('WN', 1, 10),
+        'Echo10m': ('WN', 50, 10),
+        'Fm01_B0': ('WN', 1, 10),
+        'Fm01_B1': ('WN', 1, 10),
+        'Fp_M': ('WN', 1, 10),
+        'H10Z': ('WN', 1, 10),
+        'ND10': ('WN', 1, 10),
+        'Ndlr_H': ('WN', 1, 10),
+        'Ndlr_R': ('WN', 1, 10),
+        'Nd_x': ('WN', 1, 10),
+        'Nd_y': ('WN', 1, 10),
+        'Nd_z': ('WN', 1, 10),
+        'Ngd10P': ('WN', 1, 10),
+        'Ngd10Pm': ('WN', 50, 10),
+        'Ngd_xP': ('WN', 1, 10),
+        'Ngd_yP': ('WN', 1, 10),
+        'Ngd_zP': ('WN', 1, 10),
+        'NI10': ('WN', 1, 10),
+        'Ni_x': ('WN', 1, 10),
+        'Ndfe_G9': ('WN', 1, 10),
+        'Ndfe_G8': ('WN', 1, 10),
+        'Ndfe_G7': ('WN', 1, 10),
+        'Ndfe_B0': ('WN', 1, 10),
+        'Ndfe_B1': ('WN', 1, 10),
+        'Ndfe_B2': ('WN', 1, 10),
+        'Ndfe_B3': ('WN', 1, 10),
+        'Ndfe_B4': ('WN', 1, 10),
+        'Ndfe_G1': ('WN', 1, 10),
+        'Ndfe_G10': ('WN', 1, 10),
+        'Ndfe_G2': ('WN', 1, 10),
+        'Ndfe_G3': ('WN', 1, 10),
+        'Ndfe_G4': ('WN', 1, 10),
+        'Ndfe_G5': ('WN', 1, 10),
+        'Ndfe_G6': ('WN', 1, 10),
+        'Ni_y': ('WN', 1, 10),
+        'Ni_z': ('WN', 1, 10),
+        'PQFF10': ('WN', 1, 10),
+        'PQNH10': ('WN', 1, 10),
+        'PW10': ('WN', 1, 10),
+        'Q10': ('WN', 1, 10),
+        'Q10V': ('VW', 1, 10),
+        'S0bh': ('WN', 1, 10),
+        'S0bh10': ('WN', 51, 10),
+        'S0bh_B0': ('WN', 1, 10),
+        'S0bh_B1': ('WN', 1, 10),
+        'S0bh_B2': ('WN', 1, 10),
+        'S0bh_B3': ('WN', 1, 10),
+        'S0bh_B4': ('WN', 1, 10),
+        'PQFE10': ('WN', 1, 10),
+        'PH': ('WN', 1, 10),
+        'PC10': ('WN', 1, 10),
+        'NtrackS': ('WN', 1, 10),
+        'Nu_x': ('WN', 1, 10),
+        'Nu_y': ('WN', 1, 10),
+        'Nu_z': ('WN', 1, 10),
+        'Nv_x': ('WN', 1, 10),
+        'Nv_y': ('WN', 1, 10),
+        'Nv_z': ('WN', 1, 10),
+        'Nwt_zP': ('WN', 1, 10),
+        'NzoekS': ('WN', 1, 10),
+        'OL10S': ('WN', 1, 10),
+        'OT10': ('WN', 1, 10),
+        'P10': ('WN', 1, 10),
+        'S0bh_G1': ('WN', 1, 10),
+        'H10ZV': ('VW', 1, 10),
+        'Hm0_B2': ('WN', 1, 10),
+        'Hm0_B3': ('WN', 1, 10),
+        'Hm0_B4': ('WN', 1, 10),
+        'Hm0_G1': ('WN', 1, 10),
+        'Hm0_G10': ('WN', 1, 10),
+        'Hm0_G2': ('WN', 1, 10),
+        'Hm0_G4': ('WN', 1, 10),
+        'Hm0_G5': ('WN', 1, 10),
+        'Hm0_G6': ('WN', 1, 10),
+        'Hm0_G7': ('WN', 1, 10),
+        'Hm0_G8': ('WN', 1, 10),
+        'Hm0_G9': ('WN', 1, 10),
+        'Hm0_B1': ('WN', 1, 10),
+        'Hm0_B0': ('WN', 1, 10),
+        'Hm0V': ('VW', 1, 10),
+        'H1d10': ('WN', 1, 10),
+        'H1d3': ('WN', 1, 10),
+        'H1d3V': ('VW', 1, 10),
+        'H1d50': ('WN', 1, 10),
+        'Hb10': ('WN', 1, 10),
+        'HCM': ('WN', 1, 10),
+        'HG10': ('WN', 1, 10),
+        'HG10Z': ('WN', 1, 10),
+        'HH10': ('WN', 1, 10),
+        'HH10S': ('WN', 1, 10),
+        'HMR': ('BL', 159, 10),
+        'Hm0': ('WN', 1, 10),
+        'Hm0_M': ('WN', 1, 10),
+        'Hmax': ('WN', 1, 10),
+        'HS7': ('WN', 1, 10),
+        'LG10': ('WN', 48, 10),
+        'LGK10V': ('VW', 1, 10),
+        'LGNf_z': ('WN', 1, 10),
+        'LGNik_z': ('WN', 1, 10),
+        'LGNvd_z': ('WN', 1, 10),
+        'LGNv_z': ('WN', 1, 10),
+        'M0': ('WN', 1, 10),
+        'M0_M': ('WN', 1, 10),
+        'MDG10': ('WN', 1, 10),
+        'MIN10': ('WN', 1, 10),
+        'MNR10': ('WN', 1, 10),
+        'L10': ('WN', 1, 10),
+        'KT10P': ('WN', 1, 10),
+        'HTE3': ('WN', 1, 10),
+        'Hm0_G3': ('WN', 1, 10),
+        'NB10S': ('WN', 1, 10),
+        'HTE3V': ('VW', 1, 10),
+        'I10': ('WN', 1, 10),
+        'JNR10': ('WN', 1, 10),
+        'IL10P': ('WN', 1, 10),
+        'JDG10': ('WN', 1, 10),
+        'xQ30': ('WN', 1, 30),
+        'xNI30': ('WN', 1, 30),
+        'xH30': ('WN', 1, 30),
+        'xH30R': ('WN', 1, 30),
+        'xH60': ('WN', 1, 60),
+        'xNI60': ('WN', 1, 60),
+        'xQ60': ('WN', 1, 60),
+        'xH60R': ('WN', 1, 60)
+    }
 
     def __init__(self, user=None, password=None,
             host="sip-lmw.rws.nl", port=443, meetnet="LMW", ssl = True,
@@ -79,6 +541,13 @@ Opens the connection and logs in.
                 self.reconnecttime = reconnecttime
                 self.idlereconnect = idlereconnect
 
+    def period(self, parameter):
+        if parameter in self.lmwParameters:
+            return(self.lmwParameters[parameter][2])
+        else:
+           raise LmwParmWarn(parameter)
+           return(None)
+
     def lasttime(self, parameter):
         #
         # Find the last valid 10 minute window.
@@ -371,12 +840,13 @@ Returns a single string value or None
         m = (window.seconds % 3600)//60
         return("+%02i:%02i" % (h, m))
 
-    def _roundtime_(self, time, parameter):
+    def _roundtime_(self, time, delta):
+        # Todo check: delta != 1 en delta != 10
         if time.microsecond != 0:
             time += timedelta(microseconds=1000000-time.microsecond)
         if time.second != 0:
             time += timedelta(seconds=60-time.second)
-        if (parameter.find("10") != -1) and (time.minute % 10 != 0):
+        if (delta == timedelta(minutes=10)) and (time.minute % 10 != 0):
                 time += timedelta(minutes=(10-time.minute%10))
         return(time)
 
@@ -408,13 +878,14 @@ Errors:
     endTime - startTime > 24 hour
     now - startTime < 30 days
 """
-        startTime = self._roundtime_(startTime.astimezone(tz.gettz('GMT+1')), parameter)
-        endTime   = endTime.astimezone(tz.gettz('GMT+1'))
-
-        if (parameter.find("10") != -1):
+        try:
+           delta = timedelta(minutes=self.period(parameter))
+        except Exception as e:
             delta = timedelta(minutes=10)
-        else:
-            delta = timedelta(minutes=1)
+            raise(e)
+
+        startTime = self._roundtime_(startTime.astimezone(tz.gettz('GMT+1')), delta)
+        endTime   = endTime.astimezone(tz.gettz('GMT+1'))
 
         if startTime > endTime:
             self.log.warning("starttime > endtime: %s > %s", startTime, endTime)
@@ -553,3 +1024,11 @@ class LmwCmdWarn(Warning):
 
     def __str__(self):
         return("Cmd %s failed: %s" %(self.cmd, self.message))
+
+class LmwParmWarn(Warning):
+    """Exception for a unknown parameter"""
+    def __init__(self, parameter):
+        self.parameter = parameter
+
+    def __str__(self):
+        return("Unknown parameter: %s" % parameter)
diff --git a/lmwsip/tests/__init__.py b/lmwsip/tests/__init__.py
index 6017a73..e9e7782 100755
--- a/lmwsip/tests/__init__.py
+++ b/lmwsip/tests/__init__.py
@@ -38,6 +38,23 @@ class lmwsipTest(unittest.TestCase):
         self.login()
         self.assertEqual(type(self.sip), lmwsip.LmwSip)
 
+    def test_H1(self):
+        self.sip = lmwsip.LmwSip()
+        self.assertEqual(self.sip.period('H1'), 1)
+
+    def test_H10(self):
+        self.sip = lmwsip.LmwSip()
+        self.assertEqual(self.sip.period('H10'), 10)
+
+    def test_xHm0(self):
+        self.sip = lmwsip.LmwSip()
+        self.assertEqual(self.sip.period('xHm0'), 10)
+
+    def test_Noparm(self):
+        self.sip = lmwsip.LmwSip()
+        with self.assertRaises(lmwsip.LmwParmWarn):
+            self.assertEqual(self.sip.period('Noparm'), None)
+
     def test_loginfail(self):
         with self.assertRaises(lmwsip.LmwLoginFailure):
             self.sip = lmwsip.LmwSip("FAIL", "FAIL", "localhost",
@@ -53,16 +70,16 @@ class lmwsipTest(unittest.TestCase):
 
     def test_cmd(self):
         self.login()
-        self.assertEqual(type(self.sip.cmd("WN", "DUMMY", "D10", "+00:59", "2020-01-01", "00:00")), str)
+        self.assertEqual(type(self.sip.cmd("WN", "DUMMY", "H10", "+00:59", "2020-01-01", "00:00")), str)
 
     def test_cmderr(self):
         self.login()
         with self.assertRaises(lmwsip.LmwCmdWarn):
-            self.assertEqual(type(self.sip.cmd("NOP", "DUMMY", "D10", "+00:59", "2020-01-01", "00:00")), str)
+            self.assertEqual(type(self.sip.cmd("NOP", "DUMMY", "H10", "+00:59", "2020-01-01", "00:00")), str)
 
     def test_value(self):
         self.login()
-        self.assertEqual(type(self.sip.value("WN", "DUMMY", "D10")), str)
+        self.assertEqual(type(self.sip.value("WN", "DUMMY", "H10")), str)
 
     def test_logout(self):
         self.login()
@@ -71,7 +88,7 @@ class lmwsipTest(unittest.TestCase):
     def test_lmwTimeSerie(self):
         self.login()
         timezone = tz.gettz('GMT+1')
-        res = self.sip.timeSerie("WN", "DUMMY", "D10",
+        res = self.sip.timeSerie("WN", "DUMMY", "H10",
                                   datetime.now(timezone)-timedelta(minutes=60),
                                   datetime.now(timezone))
         self.assertEqual(type(res.ts), list)
@@ -83,8 +100,8 @@ class lmwsipTest(unittest.TestCase):
         timezone = tz.gettz('GMT+1')
         t1 = datetime(2020, 1, 1, 0, 10, 0, 0, timezone)
         t2 = datetime(2020, 1, 1, 0,  0, 0, 1, timezone)
-        self.assertEqual(self.sip._roundtime_(t1, "D10"), t1)
-        self.assertEqual(self.sip._roundtime_(t2, "D10"), t1)
+        self.assertEqual(self.sip._roundtime_(t1, timedelta(minutes=10)), t1)
+        self.assertEqual(self.sip._roundtime_(t2, timedelta(minutes=10)), t1)
 
     def test_closerecv(self):
         self.login()
@@ -100,7 +117,7 @@ class lmwsipTest(unittest.TestCase):
     def test_closecmd(self):
         self.login()
         self.sip.send("CLOSE")
-        self.assertEqual(type(self.sip.cmd("WN", "DUMMY", "D10", "+00:59", "2020-01-01", "00:00")), str)
+        self.assertEqual(type(self.sip.cmd("WN", "DUMMY", "H10", "+00:59", "2020-01-01", "00:00")), str)
 
     def test_reconnect(self):
         self.login(reconnecttime=1)
diff --git a/lmwsip/tests/stubSipServer.py b/lmwsip/tests/stubSipServer.py
index 5859ec5..e8ebfbb 100755
--- a/lmwsip/tests/stubSipServer.py
+++ b/lmwsip/tests/stubSipServer.py
@@ -13,10 +13,10 @@ Implements the following commands:
   CMD> TI LMW
   ANS< ! 20-JAN-01 00:00:00
 
-  CMD> WN LMW,DUMMY,D10,+HH:MM,yyyy-mm-dd,HH:MM,DATA
+  CMD> WN LMW,DUMMY,H10,+HH:MM,yyyy-mm-dd,HH:MM,DATA
   ANS< ! 1/10,;2/10;....
 
-  CMD> WN LMW,DUMMY,D10,+HH:MM,yyyy-mm-dd,HH:MM,DATB
+  CMD> WN LMW,DUMMY,H10,+HH:MM,yyyy-mm-dd,HH:MM,DATB
   ANS< ! 1/10/0;2/10/0;....
 
   CMD> LO
@@ -86,7 +86,7 @@ class sipProtocol(socketserver.BaseRequestHandler):
                 self.send("!")
             elif self.match("TI LMW"):
                 self.send("! 20-JAN-01 00:00:00")
-            elif self.match("WN LMW,DUMMY,D10"):
+            elif self.match("WN LMW,DUMMY,H10"):
                 self.meting()
             elif self.match("LOGOUTCOUNT"):
                 self.send(str(logoutcount))
diff --git a/setup.py b/setup.py
index 7441587..54ed029 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,7 @@ with open("README.md", "r") as fh:
 
 setuptools.setup(
     name="lmwsip", # Replace with your own username
-    version="0.0.9",
+    version="0.0.10",
     author="Marcel Nijenhof",
     author_email="pip@pion.xs4all.nl",
     description="Interface for the lmw sip protocol",