The problem you have is most likely a hardware error and is not related to software . The injector tower senses the turret position and may be having trouble with finding its proper positions. The most likely fix is an exchange of the tower at our Field Repair Center .
Thank you James. I look forward to follow your suggestion.
Model # 18593B
Serial # 3427A39237
the 18593A is an very old tower - now the injector towers are using an so called vial stripper - this is the metal part which is moved by the plastic turret during injection between the vial and the needle, this part uses an spring to always have contact to the turret during it is turning.
now after years it will get sticky - and the turret moves to slow and you will get an turret error
now to solve this
remove the plastic turret ( lift it up from the turret motor )
the vial stripper (metal part) can be moved nearly 90 degrees
in the left back corner of the tower you can see the that there is the mentioned spring
put some sew machine oil drops on that axis
turn the vial stripper 10-20 times back and let him driven by the spring come back out to the front
you will feel that the movement goes easier then before
repeat the steps if required.
push the vial stripper back and remount the plastic turret ( fits only in one position on to the turret motor )
now in most cases ( if the motor is not defective ) this solves problem