TABLE 2/T.30 Bit No. DIS/DTC DCS 1 Transmitter – T.2 operation 2 Receiver – T.2 operation Receiver – T.2 operation 3 T.2 IOC = 176 T.2 IOC = 176 4 Transmitter – T.3 operation 5 Receiver – T.3 operation Receiver – T.3 operation 6 Reserved for future T.3 operation features 7 Reserved for future T.3 operation features 8 Reserved for future T.3 operation features 9 Transmitter – T.4 operation 10 Receiver – T.4 operation Receiver – T.4 operation 11, 12, Data signalling rate Data signalling rate 13, 14 V.27 ter fall back mode 12 400 bit/s, V.27 ter 10, 10, V.27 ter 14 800 bit/s, V.27 ter 10, 10 V.29 19 600 bit/s, V.29 10, 11, V.27 ter and V.29 17 200 bit/s, V.29 10, 10 Not used 14 400 bit/s, V.33 11, 10, Reserved 12 000 bit/s, V.33 10, 10 Not used Reserved 11, 11, V.27 ter, V.29 and V.33 Reserved 10, 10 Not used 14 400 bit/s, V.17 10, 10, Reserved 12 000 bit/s, V.17 11, 10 Not used 19 600 bit/s, V.17 10, 11, V.27 ter, V.29, V.33 and 17 200 bit/s, V.17 11, 10 V.17 Reserved 11, 10, Not used Reserved 11, 10 Reserved Reserved 11, 11, Not used Reserved 11, 10 Reserved 10, 10, 10, 11 10, 11, 10, 11 11, 10, 10, 11 11, 11, 10, 11 10, 10, 11, 11 10, 11, 11, 11 11, 10, 11, 11 11, 11, 11, 11 15 Vertical resolution – 7.7 Vertical resolution – 7.7 line/mm line/mm 16 Two-dimensional coding Two-dimensional coding capability 17, 18 Recording width Recording width (0,0) capabilities 1728 picture elements 1728 picture elements along scan line length of (0,1) along scan line length of 215 mm ± 1% 215 mm ± 1% 2432 picture elements 1728 picture elements along scan line length of along scan line length of 303 mm ± 1% 215 mm ± 1% and 2048 picture elements (1,0) along scan line length of 255 mm ± 1% and 2432 picture elements 2048 picture elements along scan line length of along scan line length of (1,1) 303 mm ± 1% 255 mm ± 1% 1728 picture elements along scan line length of 215 mm ± 1% and Invalid 2048 picture elements along scan line length of 255 mm ± 1% Invalid (see Note 7) 19, 20 Maximum recording length Maximum recording length (0,0) capability A4 (297 mm) (0,1) A4 (297 mm) Unlimited (1,0) Unlimited B4 (364 mm) (1,1) A4 (297 mm) and B4 (364 Invalid mm) Invalid TABLE 2/T.30 (Cont.) Bit No. DIS/DTC DCS 21, 22, Minimum scan line time Minimum scan line time 23 capability at the receiver 20 ms (0, 0, 20 ms at 3,85 1/mm: T7,7 = 40 ms 0) T3,85 10 ms (0, 0, 40 ms at 3.85 1/mm: T7.7 = 45 ms 1) T3.85 (0, 1, 10 ms at 3.85 1/mm: T7.7 = 0) T3.85 (1, 0, 15 ms at 3.85 1/mm: T7.7 = 40 ms 0) T3.85 (0, 1, 10 ms at 3.85 1/mm: T7.7 = 1) 1/2 T3.85 (1, 1, 20 ms at 3.85 1/mm: T7.7 = 0) 1/2 T3.85 (1, 0, 40 ms at 3.85 1/mm: T7.7 = 1) 1/2 T3.85 (1, 1, 00 ms at 3.85 1/mm: T7.7 = 1) T3.85 24 Extend field Extend field 25 2400 bit/s handshaking 2400 bit/s handshaking 26 Uncompressed mode Uncompressed mode 27 Error correction mode Error correction mode 28 Set to “0” Frame size 0 = 256 octets Frame size 1 = 264 octets 29 Error limiting mode Error limiting mode 30 Reserved for G4 capability Reserved for G4 capability on PSTN on PSTN 31 T.6 coding capability T.6 coding enabled 32 Extend field Extend field 33 Validity of bits 17, 18 Recording width (0) Bits 17, 18 are valid Recording width indicated (1) Bits 17, 18 are invalid by bits 17, 18 Recording width indicated by this field bit information 34 Recording width Middle 1216 elements of capability: 1728 picture elements 1216 picture elements along scan line length of 151 mm ± 1% 35 Recording width Middle 864 elements of capability: 1728 picture elements 864 picture elements along scan line length of 107 mm ± 1% 36 Recording width Invalid capability: 1728 picture elements along scan line length of 151 mm ± 1% 37 Recording width Invalid capability: 1728 picture elements along scan line length of 107 mm ± 1% 38 Reserved for future recording width capability 39 Reserved for future recording width capability 40 Extend field Extend field Notes to Table 2/T.30 Note 1 – Standard facsimile units conforming to T.2 must have the following capability: Index of cooperation (IOC) = 264. Note 2 – Standard facsimile units conforming to T.3 must have the following capability: Index of cooperation (IOC) = 264. Note 3 – Standard facsimile units conforming to T.4 must have the following capability: Paper length = 297 mm. Note 4 – Where the DIS or DTC frame defines V.27 ter capabilities, the equipment may be assumed to be operable at either 4800 or 2400 bit/s. Where the DIS or DTC frame defines V.29 capabilities, the equipment may be assumed to be operable at either 9600 or 7200 bit/s per V.29, where it defines V.33 capabilities, the equipment may be assumed to be operable at either 14 400 bit/s or 12 000 bit/s per V.33 and where it defines V.17, the equipment may be assumed to be operable at 14 400 bit/s, 12 000 bit/s, 9600 bit/s or 7200 bit/s per V.17. Note 5 – T7.7 and T3.85 refer to the scan line times to be utilized when the vertical resolution is 7.7 lines/mm or 3.85 lines/mm, respectively (see bit 15 above). T7.7 = 1/2 T3.85 indicates that in the high resolution mode, the scan line time can be decreased by half. Note 6 – The standard FIF field for the DIS, DTC and DCS signals is 24 bits long. If the "extended field" bit(s) is a 1, the FIF field shall be extended by an additional eight bits. Note 7 – Existing equipment may send the invalid (1,1) condition for bits 17 and 18 of their DIS signal. If such signal is received, it should be interpreted as (0,1). Note 8 – The values of bit No. 28 in the DCS command is valid only when the indication of the T.4 error correction mode is invoked by bit 27. Note 9 – When bit 33 is set to 1 in DCS, the meaning of bit 15 originally defined to indicate 7.7/mm vertical resolution is modified to mean a higher resolution. Note 10 – When the recording width is A4 only, the field consisting of bits 33-40 need not be present. Note 11 – The optional T.4 error correction mode of operation requires 0 ms of the minimum scan line time capability. Bits 21-23 in DIS/DTC signals indicate the minimum scan line time of a receiver regardless of the availability of the error correction mode. In case of error correction mode, the sender sends DCS signal with bits 21-23 set to 1.1.1 indicating 0 ms capability. In case of normal G3 transmission, the sender sends DCS signal with bits 21-23 set to the appropriateness according to the capabilities of the two machines. Note 12 – T.6 coding scheme capability specified by bit 31 is valid only when bit 27 (error correction mode) is set as a “1” .