Of course the ETU01A as a communications device has a DCE data port. But there are applications, especially that include wireless transmission, where the DCE port must connect to another DCE.
Remember the interface is always physical DCE, so the systems integrator will be required to make their own "cross-over" cable before connecting to other DCE equipment. The cable is NOT documented in the manual, nor do we supply this type of non-standard cable.

   ETU-01A side         Equipment(DCE type)
     1   Shield            1   Shield
     8   G                 8   G
     2   T(A)              4   R(A)
     9   T(B)              11  R(B)
     4   R(A)              2   T(A)
     11  R(B)              9   T(B)
     3   C(A)              5   I(A)
     10  C(B)              12  I(B)
     5   I(A)              3   C(A)
     12  I(B)              10  C(B)
    *7   X(A)              6   S(A)
    *14  X(B)              13  S(B)

* The X signal is an External Transmit Clock (ETC) which is not part of the ITU-T X.21 standard. However, we have supplied this proprietary connection for applications such as this, where the physical DCE must act as a DTE and receive clock signal from a connected DCE device.

The ETU01A clock mode must be set to "DTE3". By using this cross cable, the ETU-01A performs as a DTE. The equipment must provide clock source to ETU01A. Note: The same (A) and (B) signal pairs must use a twisted pair in the cable.