The GT27, GT25, or GT21 model (Ethernet connection models) can monitor up to four controllers (four channels) (such as PLC CPU, temperature controller, and inverter) simultaneously by using the multi-channel function.
Since channel 1 of the GOT is used to connect the Q06HCPU, use channel 2 to connect the Q03UDVCPU by Ethernet.
The following describes an example of settings to connect the GOT and the Ethernet port built in the Q03UDVCPU by Ethernet.
* For the GT21 model (Ethernet connection model), up to two controllers (two channels) can be monitored simultaneously.

1. Configure the following settings in GT Designer3 (GOT2000).
◆ For GT Designer3 (GOT2000) Version1.100E or later
　(1) Select [Common] → [Controller Setting] → [CH2] from the menu.
　　 Manufacturer: MITSUBISHI ELECTRIC
　　 Controller Type: MELSEC-Q/QS, Q17nD/M/NC/DR, CRnD-700
　　 I/F: Ethernet:Multi
　　　(For GT Designer3 (GOT2000) Version1.170C or earlier, Standard I/F(Ethernet): Multi)
　　 Driver: Ethernet(MITSUBISHI ELECTRIC), Gateway
　　　(For GT Designer3 (GOT2000) Version1.178L or earlier, Ethernet (MELSEC), Q17nNC, CRnD-700, Gateway)
　　 GOT Net No.: 1
　　 GOT Station: 18
　(2) Select [Common] → [Controller Setting] → [CH2] → [Ethernet Controller Setting] from the menu.
　　 Host: *
　　 Net No.: 1 (example)
　　 Station: 1 (example)
　　 Unit Type: QnUD(P)V/QnUDEH
　　 IP address 192.168.3.39
　　 Port No. 5006
　　 Communication: UDP
　(3) Select [Common] → [GOT Ethernet Setting] → [GOT IP Address Setting] → [Standard Port] from the menu.
　　(For GT Designer3 (GOT2000) Version1.170C or earlier, select [Common] → [Controller Setting] → [CH2] → [Ethernet Setting] from the menu.
　　 GOT IP address: 192.168.3.18
　　 Subnet Mask: 255.255.255.0

2. Configure the following settings in GX Works2.
　(1) Select [Parameter] → [PLC parameter] → [Built-in Ethernet Port Setting] from the menu.
　　 IP address: 192.168.3.39
　　 Subnet Mask Pattern: 255.255.255.0
　(2) Select [Parameter] → [PLC parameter] → [Built-in Ethernet Port Setting] → [Open Setting] from the menu.
　　 Protocol: UDP
　　 Open System: MELSOFT Connection

For the details, refer to the following.

? GOT2000 Series Connection Manual (Mitsubishi Electric Products) For GT Works3 Version1 (SH-081197ENG)
　"5.3 GOT Side Settings"
　"5.4 PLC Side Setting"