Solved!
In short it appears that IOS wanted the subnet mask to specifically be '255.255.0.0' whereas the Javad default is '255.255.255.0'. Big thank you to Michael Glutting, Yuri Noyanov and John Evers for taking the time out to help me solve this problem. Very impressed with the ability to access support and the efforts of all involved.
The problem and steps taken are posted below in case this is useful to others:
Initial problem: Actively using a Triumph 2 for several months controlling via Javad Mobile Tools (JMT) on an iphone (iphone #1- ios 10.3.3). Uploaded JMT app to new iphone (iphone #2- ios 10.3.3) to use with Triumph 2, unable to establish a connection with JMT even after basic troubleshooting efforts (ios resets, re-entering parameters, double-checking parameters etc.). Uploaded NetBrowser for ios to iphone #2 and was able to connect and control the Triumph 2 using that app. Completed field work using JMT on iphone #1 and NetBrowser on iphone #2.
Troubleshooting:
Step #1: updated Triumph 2 firmware, cleared NVRAM and reset (also updated OAF file after below result with no change)
Result: now completely unable to connect to Triumph 2 through either JMT or NetBrowser on either iphone #1 or #2. Able to view wifi signal and apparently connect with iphone although there is a yellow warning exclamation point through the wifi signal. Note: the iphone always warns when connecting to the Javad wifi about a lack of internet connection and provides a security recommendation (open network using 802.11b- not an issue in this case).
Step #2: updated JMT app to latest version and installed NetBrowser on iphone #1
Result: no change- still no connectivity
Step #3: Changed parameter settings via desktop NetView and Modem (matched to those provided above by Yuri)- The only parameter change: WLAN ap mode to 'wpa' from what for me was the default 'wep'. Attempted iphone connection via DHCP (rather than static as described in the Triumph 2 QuickStart Guide).
Result: still no connectivity, iphone appears to connect but qualifies connection with a yellow warning exclamation point through the wifi signal symbol. If I do not manually enter the ip address the iphone fills it in as: '169.254.164.9', the subnet mask is filled in as '255.255.0.0' (note distinct from the Javad default subnet mask parameter of 255.255.255.0 or from Yuri's parameters 255.255.255.192). Networking novice, but the 169.... IP address indicates a failure of the iphone to obtain a valid IP address.
Step #4: Via desktop NetView and Modem WLAN tab changed the network mask parameter to match the one the iphone seems to be expecting: '255.255.0.0'. Switched to static mode by changing, on WLAN tab, "Switch DHCP server on/off" to "off". On the iphone wifi network setting under the 'Static' tab manually entered the 'IP Address' as '192.168.0.2', the 'Subnet Mask' as '255.255.0.0' and the 'Router' as '192.168.0.1'. Lastly and likely incidental, but included here just in case, on the WLAN page, entered 'WLAN WPA Passphrase' as '12345678'.
Result: The iphone wifi symbol shows as complete (not bisected by the yellow warning exclamation point as before although the same security warning still appears on the signal's info page). Connection to both JMT and NetBrowser is successful!
Note: On the NetView and Modem WLAN tab turned "Switch DHCP server on/off" back to "on" and able to connect successfully with the iphone automatically filling in the correct information under it's DHCP tab.
Screenshots of relevant pages showing the working solution from NetView and Modem and ios are attached. Thanks to all!