If you want help with an error, you really have to provide the error code and message. However, a quick glance shows that you are doing a read without issuing a query command. This would result in a timeout error. If this is the case, you need to understand some of the basics of instrument communication. An instrument will not place data in it's transmit buffer for reading until it receives a query. With SCPI, a query command is terminated with a ?. Look through the programming manual to determine the query you need and then find that in the driver. I suspect that all you need to do is use the Read function set to the Digital Pattern instance.
