Is the six relay option external on the HI 2151/30WC?

I want to add a six-relay output option to HI 2151/30WC. Is this relay option internal or external to my controller? What other information can you provide?

The D1, D2, and D3 options are to add six external relays on the HI 2151/30WC. The option may or may not include the external relays, and is also configured on the Secure Memory Module (SMM).

The D1, D2 or D3 option information is as follows.

D1 - Six TTL Level Outputs are activated
Rating - 300 mA per line
Cable Length - 5 feet (1.52 meters)
NO physical relays are included.
Only the SMM and J4 cable is included. The J4 cable needs to be connected to the customer provided relay driver. This option will not directly drive relay coils.

D2 - Comes with everything in the D1 option and includes a 6 external solid state relays board.

D3 - Comes with everything in the D1 option, but the cable is only 6 inches long for use in the Wall Mount (WS) model. The D3 option includes a 6 external solid state relay board.

External Relay Board Rating
115 VAC, 3 Amperes Continuous
115VAC, 5 Amperes Momentary
Mounted on a board with Dimensions
5.7"L x 2.5"W (144.78mmL x 88.9mmW)

If you are adding the D1 option in the field you will receive a replacement Secure Memory Module and cable. If your purchase the D2 or D3 option you will get everything in the D1 option and you will also receive the relay card.  When you install the new SMM the instrument will be set back to factory defaults and will need to be installed as if it was a new instrument. The SMM information cannot be saved to a file.  Review the settings of the old SMM and record on paper.