To configure various aspects of a TN3270 session in ZOC, you will need to make changes to the program settings, session profile, and potentially in the host directory entry (or Quick Connection window) that defines the sessions.
In ZOC the settings that are used for a session that is defined in the host directory (and also in the quick-connect window) are layered in an order from general to specific:
In order to change program settings, go to Options-menu → Program Settings. You will find a range of option groups there which apply to all sessions. Therefore this will be the place where (among other things) you can configure what functions the mouse buttons perform, which printer is to be used and how text is marked on screen, etc.
In order to change session profile settings, go to Options-menu → Edit Session Profile. The session profile contains options that are related to the terminal and session itself, e.g. the cursor shape, choice of font, colors, visible window parts, etc.
However, since ZOC supports a wide variety of terminal emulations and potential uses, these options can theoretically be applied to very different types of connections, such as TN3270 sessions, Unix shell connections, and connections with attached hardware. So, while the options in the session profile are closer to making a connection, not all of them will be applicable in the context of every type of session. Consequently, certain settings listed here may not apply to TN3270 connections.
For example, since many emulations supported by ZOC follow the character stream model, ZOC offers options for local echo and CR/LF translation. These will not apply to TN3270 because a TN3720 is a block oriented terminal type.
Also, not all colors defined in the session profile are used by the TN3270 emulation, as some entries do not correspond to how TN3270 handles color. Therefore, in addition to colors and other general options, there are settings which are tailored to TN3270 sessions specifically (see below).
Similarly, the Font/Layout section allows you to configure the terminal size. However, because a TN3270 session is based on different hardware models with varying numbers of lines and columns, selecting a TN3270 model will override the more general layout settings.
Conclusion: While you will find a range of settings in the session profile which will be of interest to you while configuring a TN3270 session, not all will be relevant or even applicable.
The most applicable options for TN3270 connections are found in the options directly associated with the TN3270 emulation (see below).
As described above, the session profile contains session-related options that apply a broad spectrum of usage scenarios. However, the emulation section of the session profile also offers options which apply specifically to the TN3270 emulation and which not pertain to sessions using any other emulation type, such as VT100 or Xterm. You will find these by editing the session profile, going to the Emulation section and selecting TN3270 (see the image below).
Since the settings for the chosen emulation are part of the session profile, you can configure them while editing the session profile. This will affect all TN3270 connections that use that profile.
Alternatively, you can specify these settings in the host directory entry or in the Quick Connection window.
Let us assume you want to enable the option to swap the function of the Enter and right Ctrl key for all your TN3270 Sessions:
Let us assume you want to use the model 3279-3-E (80 columns x 32 lines) for a specific session:
The TN3270 emulation comes with built in keyboard mappings, which map 3270 keys to keys on the local keybarod. You can see these in Help-menu → Keyboard.
If you want to change any of those, you can go to Options-menu → Keyboard-Profiles and you can map TN3270 keys to local keyboard keys. This works for all keys, except for the Ctrl, Alt and Shift keys. But some mappings to the Ctrl keys (e.g. Enter/Transmit/Newline/Reset) are available as options in the TN3270 emulation specific options (see above).