The generator matrix

 1  1  1  1  1  1  1
 0  7  0  0  7  7 28
 0  0  7  0 35 28 21
 0  0  0  7 35  7 14

generates a code of length 7 over Z49 who´s minimum homogenous weight is 28.

Homogenous weight enumerator: w(x)=1x^0+210x^28+378x^35+15414x^42+804x^49

The gray image is a code over GF(7) with n=49, k=5 and d=28.
This code was found by Heurico 1.16 in 0.00913 seconds.