Maple Systems HMI5000L Series - Manual (Page 19)

HMI5000L Installation Guide 19
1010-1018 Rev 01 www.maplesystems.com
Figure 7c: Serial Port Pinouts HMI5121XL, HMI5150XL
Note: COM1 [RS-485 2W] and COM3 [RS-485 2W] support the Siemens
MPI 187.5K multi-point interface. However, only one COM port can be
used with the Siemens MPI interface at a time.