of ones of the previously described connectors 102 104 106 108 150 152 154 156 by operation of discharge control valves shown respectively at 202 204 206 208 250 252 254 and 256 selective fluid discharge can be used for various types of tests to be preformed on the earth formations 12 and 14 in fig1 as will be further explained the discharge control valves can also be electrically operated solenoid valves of a type known in the art control signals for the discharge control valves can be generated by the surface electronics 8 in fig1 in response to the system operator providing appropriate commands the control signals can be decoded in and conducted to the valves from the electronics section 16 in fig1 as will be readily understood by those skilled in the art by operating the isolation valves the additional isolation valves the pump isolation valves and the discharge control valves in the appropriate sequences the system operator can perform various tests on the earth formations 12 14 in fig1 which may be indicative of certain hydraulic properties of the earth formations 12 14 in fig1 for example the valves can be operated so as to cause the pump 164 to withdraw fluid from the formation through all four of the ports on the first seal section 18 in fig1 all of the valves connected to the flow ports on the second seal section 20 in fig1 as shown at 118 120 122 and 124 can be closed to enable differential pressure measurement to be made between any two adjacent ports on the second seal section 20 in fig1 differential pressure developed between two adjacent ports on the second seal section could be indicative of hydraulic.