A 36M is similar to having two 18Ms in one module, providing two banks whereas a 72M is similar to having four 18Ms in a single module, thereby providing four banks. You can assign each bank to a specific channel, for example, bank A assigned to channel 01 and bank B assigned to channel 02. Using the 18R or 18R2, you select a channel and fire accordingly.
On the 36M there is a CHANGE BANK button that you can press to toggle between banks A and B. For each bank, you can press and hold the CH+ or CH- buttons to change the bank for that channel, such as setting bank A to channel 01, and bank B to channel 02. You can set the bank to any channel you prefer.
To test continuity on the module, press the TEST button to have the cue LEDs display positive continuity for the selected bank. We recommend writing the channel on a small piece of masking tape and placing it next to the bank on the module or slat to notify the operator of the placement.