Sick S3000 Laser baud rate

Hello, I have a Sick S3000 Laser used primarily for safety function. I would also like to see scan messages using the `s3000_laser` ROS package. I have configured the laser using Sick's configuration utility. It now outputs measurements continuously. I am unable to use a baud rate over 38,400 Baud. When I configure the Laser scanner to a higher baud and make corresponding changes in the launch file, I either get (1) several `S3000: Checksum's dont match, thats bad (data packet size )` [ this happens with 125kBaud, 250kBaud], or, (2) simply no scan messages at all [500 kBaud]. I am using a regular Serial port configured as an RS-422 port on the computer (not a USB-RS422 adapter). The maximum freq of messages is about 2.5 Hz which is super low. Am I missing something? Should I do something more to achieve better baud rates? Any help is greatly appreciated. Thank you.