Solution
The MP500 TCL3 and MP500 PT1 were designed to be used with a dual PCD-PICC antenna for any functionality outside of the test suites. With the MP500 in card emulation mode, the load modulation amplitude is controlled through the HDMI connection from the MP500 to the dual antenna.
However, this connection does not exist on NFC Forum Listener or ISO Reference PICC antennas. In order to use a either of these antennas directly with the MP500 for card emulation mode, the user has two options.
1) The first, and easiest, option is to use an HDMI splitter which breaks out the pins of the HDMI connection and routes the load modulation signal to appropriate connection on the listener antenna as shown below.
This setup is mandatory if the user desires to implement a variable load modulation.
2) The second option is to use the TCL2 compatibility mode. This requires the use of the ChannelSetParameter remote command, CHCP 0 1. Note: In this configuration, the MP500 is incapable of generating a variable load modulation amplitude.