How do I zero the scale at power up using a HI 1771WS?

I am using a 1771WS series A module. I need to zero the scale at power-up. The incoming weight reads 4000 lbs. The net value reads 4000 lbs. When I tare the scale the net value is now 0 lbs. This is OK. At power-up the incoming and net now read 4000 lbs. I have tried to zero the scale, but it doesn't seem to work. I need the required PLC-5 ladder to perform a zeroing function at power-up.

There are two considerations to zero the scale.

First is motion. If the scale is in motion, then the module will not zero. If motion is a problem, it may indicate that the motion tolerance is set too low. This setting should be just larger than the amount of fluctuation seen on the reading with no weight changing on the scale.

Second is the zero tolerance. This is the cumulative total amount of gross weight allowed to be zeroed off. If the current gross weight exceeds the zero tolerance, or if the current gross weight plus any previously zeroed amount exceeds the tolerance, then the unit will not zero.

The zero function is instigated by setting word 2, bit 1 in the write buffer to a 1 and initiate the block write. After the module has zeroed the weight or failed, you would change word 2, bit 1 back to a 0 and initiate the block write again. If the module fails to zero the weight, it should respond with an error bit in word 0 of the read buffer.