I have called volusion API from PHP using cURL to get all products using generic/all_products url. Finally I have listed the product attributes in XML format.
Is it possibille to call custom field attributes for a product in volusion while getting all products with their attributes.
If you want to include the custom fields for a product, include the columns like this in your url (note the "pe" table prefix)
SELECT_Columns=p.ProductCode,pe.CustomField1,pe.CustomField2,pe.CustomField3,pe.CustomField4,pe.CustomField5
NOTE: this works with "EDI_Name=Generic\Products", since it allows you to specify the where clause and select the columns you need.
According to Volusion's "documentation" for All Products, it looks like the field list is pre-determined and does not include custom fields.