Well, you keep leaving out important details, but I'll offer the following:
1) There is no -12 VDC. It's just the ground for the 12 VDC power supply. Otherwise, you have a major problem!
2) I don't see a 24 VDC power supply, so I'm assuming that it connects to terminals TB1-3 and TB1-4 as indicated in Figure 2-13.
3) There is no GND connection on TB1, so this is probably wrong.
4) The loop resistor should be connected between TB1-2 and ground.
5) The loop power supply should be connected to TB1-1.
6) The DS2438 Vad should be connected to TB1-2.
7) The DS2438 Vsens+ and Vsens- should be connected to ground.
8) Your loop current to voltage conversions are backwards.
9) You need a 4.7K ohm pull up on DQ.