The restrict implicit binary conversion mode (CONVERSION_MODE set to 1) applies to certain types of UPDATE.
UPDATE SET VALUE FROM expression (including constant)
UPDATE SET VALUE FROM other column
UPDATE SET VALUE FROM host variable
JOIN UPDATE SET VALUE FROM column of other table
Example
This request:
UPDATE t1 SET cbi=cbn WHERE c1=1
fails with the message:
"Unable to implicitly convert column 'cbi' to datatype (bigint) from datatype (binary). [-1000187] ['QCB87']"