You are likely getting an error message from the Momentum PLC if trying to do a block write into the 42000 mirrored address space on the 982EN/983EN modules. However, all the Acromag units support other 40000 registers which should work fine and offer faster performance.
Model 982EN/983EN-4012: Use Register 40011. This is a single 16-bit register that will drive all 12 outputs in a single write command.
Model 989EN-4xxxx: Use Register 40040. This is a single 16-bit register that will drive all 16 outputs in a single write command.
Model ES2113-xxxx: Use Registers 40060 through 40065. These six 16-bit registers will drive all 96 channel outputs on the ES2113. Each register drives a port of 16 channel outputs. This address space also supports the "Preset Multiple Register" command, so you can do a block write to all six registers if needed.